diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f90995d13..84c913a9d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -23,7 +23,7 @@ repos:
     name: Blacken
 
 - repo: https://github.com/PyCQA/bandit
-  rev: '1.7.4'
+  rev: '1.7.5'
   hooks:
   - id: bandit
     args: [-r]
diff --git a/docs/tools-instructions.md b/docs/tools-instructions.md
index 0066cb2fb..133593c62 100644
--- a/docs/tools-instructions.md
+++ b/docs/tools-instructions.md
@@ -167,9 +167,9 @@ optional arguments:
                         Note: FaCT++ is preferred with EMMO.
   --root ROOT, -r ROOT  Name of root node in the graph. Defaults to all
                         classes.
-  --leafs LEAFS         Leafs nodes for plotting sub-graphs. May be provided
+  --leaves LEAVES       Leaf nodes for plotting sub-graphs. May be provided
                         as a comma-separated string and/or with multiple
-                        --leafs options.
+                        --leaves options.
   --exclude EXCLUDE, -E EXCLUDE
                         Nodes, including their subclasses, to exclude from
                         sub-graphs. May be provided as a comma-separated
diff --git a/examples/emmodoc/emmo.md b/examples/emmodoc/emmo.md
index 5e3626823..4f1e2aa6d 100644
--- a/examples/emmodoc/emmo.md
+++ b/examples/emmodoc/emmo.md
@@ -21,4 +21,4 @@
 %BRANCHFIG EMMORelation   caption='The complete taxonomy of EMMO relations.' terminated=0 relations=all edgelabels=0
 
 %HEADER "The taxonomy of EMMO classes"     level=2
-%BRANCHFIG EMMO           caption='The almost complete taxonomy of EMMO classes. Only physical quantities and constants are left out.' terminated=0 relations=isA edgelabels=0 leafs=PhysicalDimension,BaseQuantity,DerivedQuantity,ExactConstant,MeasuredConstant,SIBaseUnit,SISpecialUnit,MetricPrefix,UTF8
+%BRANCHFIG EMMO           caption='The almost complete taxonomy of EMMO classes. Only physical quantities and constants are left out.' terminated=0 relations=isA edgelabels=0 leaves=PhysicalDimension,BaseQuantity,DerivedQuantity,ExactConstant,MeasuredConstant,SIBaseUnit,SISpecialUnit,MetricPrefix,UTF8
diff --git a/examples/emmodoc/introduction.md b/examples/emmodoc/introduction.md
index 8e314ceee..c06eb040a 100644
--- a/examples/emmodoc/introduction.md
+++ b/examples/emmodoc/introduction.md
@@ -75,7 +75,7 @@ For instance, in the graph of the top-level entity branch below, The root `EMMO`
 Non-defined classes are defined as an abstract group of objects, whose members are defined as belonging to the class.
 They are yellow in the graphical representations.
 
-%BRANCHFIG EMMO leafs=Perspective,Elementary caption='Example of the top-level branch of EMMO showing some classes and relationships between them.' width=460
+%BRANCHFIG EMMO leaves=Perspective,Elementary caption='Example of the top-level branch of EMMO showing some classes and relationships between them.' width=460
 
 ### Axioms
 
diff --git a/examples/jupyter-visualization/emmographs.ipynb b/examples/jupyter-visualization/emmographs.ipynb
index 1bd33ad4c..a94cd51d5 100644
--- a/examples/jupyter-visualization/emmographs.ipynb
+++ b/examples/jupyter-visualization/emmographs.ipynb
@@ -45,10 +45,10 @@
     }
    ],
    "source": [
-    "leafs = set()\n",
+    "leaves = set()\n",
     "for s in onto.Perspective.subclasses():\n",
-    "    leafs.update(s.subclasses())\n",
-    "graph = OntoGraph(onto, onto.Perspective, leafs=leafs, parents=1, edgelabels=True)\n",
+    "    leaves.update(s.subclasses())\n",
+    "graph = OntoGraph(onto, onto.Perspective, leaves=leaves, parents=1, edgelabels=True)\n",
     "\n",
     "graph.dot\n",
     "#graph = OntoGraph(onto, onto.isA, leafs=('Physical',))\n",
diff --git a/ontopy/graph.py b/ontopy/graph.py
index fdba5f156..569dd5225 100644
--- a/ontopy/graph.py
+++ b/ontopy/graph.py
@@ -166,7 +166,7 @@ class OntoGraph:  # pylint: disable=too-many-instance-attributes
         Name or owlready2 entity of root node to plot subgraph
         below.  If `root` is `graph.ALL`, all classes will be included
         in the subgraph.
-    leafs : None | sequence
+    leaves : None | sequence
         A sequence of leaf node names for generating sub-graphs.
     entities : None | sequence
         A sequence of entities to add to the graph.
@@ -236,7 +236,7 @@ def __init__(  # pylint: disable=too-many-arguments,too-many-locals
         self,
         ontology,
         root=None,
-        leafs=None,
+        leaves=None,
         entities=None,
         relations="isA",
         style=None,
@@ -293,7 +293,7 @@ def __init__(  # pylint: disable=too-many-arguments,too-many-locals
         elif root:
             self.add_branch(
                 root,
-                leafs,
+                leaves,
                 relations=relations,
                 edgelabels=edgelabels,
                 addnodes=addnodes,
@@ -350,9 +350,9 @@ def add_entities(  # pylint: disable=too-many-arguments
     def add_branch(  # pylint: disable=too-many-arguments,too-many-locals
         self,
         root,
-        leafs=None,
-        include_leafs=True,
-        strict_leafs=False,
+        leaves=None,
+        include_leaves=True,
+        strict_leaves=False,
         exclude=None,
         relations="isA",
         edgelabels=None,
@@ -363,17 +363,17 @@ def add_branch(  # pylint: disable=too-many-arguments,too-many-locals
         include_parents="closest",
         **attrs,
     ):
-        """Adds branch under `root` ending at any entiry included in the
-        sequence `leafs`.  If `include_leafs` is true, leafs classes are
+        """Adds branch under `root` ending at any entity included in the
+        sequence `leaves`.  If `include_leaves` is true, leaf classes are
         also included."""
-        if leafs is None:
-            leafs = ()
+        if leaves is None:
+            leaves = ()
 
         classes = self.ontology.get_branch(
             root=root,
-            leafs=leafs,
-            include_leafs=include_leafs,
-            strict_leafs=strict_leafs,
+            leaves=leaves,
+            include_leaves=include_leaves,
+            strict_leaves=strict_leaves,
             exclude=exclude,
         )
 
@@ -385,7 +385,7 @@ def add_branch(  # pylint: disable=too-many-arguments,too-many-locals
 
         nodeattrs = {}
         nodeattrs[get_label(root)] = self.style.get("root", {})
-        for leaf in leafs:
+        for leaf in leaves:
             nodeattrs[get_label(leaf)] = self.style.get("leaf", {})
 
         self.add_entities(
diff --git a/ontopy/ontodoc.py b/ontopy/ontodoc.py
index efdad809f..bfd5ad412 100644
--- a/ontopy/ontodoc.py
+++ b/ontopy/ontodoc.py
@@ -518,9 +518,10 @@ class DocPP:  # pylint: disable=too-many-instance-attributes
           - header_level: Header level.
           - terminated: Whether to branch should be terminated at all branch
             names in the final document.
-          - include_leafs: Whether to include leaf.
+          - include_leaves: Whether to include leaves as end points
+            to the branch.
 
-            %BRANCH name [header_level=3 terminated=1 include_leafs=0
+            %BRANCH name [header_level=3 terminated=1 include_leaves=0
                           namespaces='' ontologies='']
 
       * Insert generated figure of ontology branch `name`.  The figure
@@ -528,17 +529,17 @@ class DocPP:  # pylint: disable=too-many-instance-attributes
         where `figdir` is given at class initiation. It is recommended
         to exclude the file extension from `path`.  In this case, the
         default figformat will be used (and easily adjusted to the
-        correct format required by the backend). `leafs` may be a comma-
+        correct format required by the backend). `leaves` may be a comma-
         separated list of leaf node names.
 
-            %BRANCHFIG name [path='' caption='' terminated=1 include_leafs=1
-                             strict_leafs=1, width=0px leafs='' relations=all
+            %BRANCHFIG name [path='' caption='' terminated=1 include_leaves=1
+                             strict_leaves=1, width=0px leaves='' relations=all
                              edgelabels=0 namespaces='' ontologies='']
 
       * This is a combination of the %HEADER and %BRANCHFIG directives.
 
             %BRANCHHEAD name [level=2  path='' caption='' terminated=1
-                              include_leafs=1 width=0px leafs='']
+                              include_leaves=1 width=0px leaves='']
 
       * This is a combination of the %HEADER, %BRANCHFIG and %BRANCH
         directives. It inserts documentation of branch `name`, with a
@@ -546,7 +547,7 @@ class DocPP:  # pylint: disable=too-many-instance-attributes
         element.
 
             %BRANCHDOC name [level=2  path='' title='' caption='' terminated=1
-                             strict_leafs=1 width=0px leafs='' relations='all'
+                             strict_leaves=1 width=0px leaves='' relations='all'
                              rankdir='BT' legend=1 namespaces='' ontologies='']
 
       * Insert generated documentation for all entities of the given type.
@@ -723,11 +724,11 @@ def process_branches(self):
                     tokens[2:],
                     header_level=3,
                     terminated=1,
-                    include_leafs=0,
+                    include_leaves=0,
                     namespaces="",
                     ontologies="",
                 )
-                leafs = (
+                leaves = (
                     names if opts.terminated else ()
                 )  # pylint: disable=no-member
 
@@ -744,7 +745,7 @@ def process_branches(self):
 
                 branch = filter_classes(
                     onto.get_branch(
-                        name, leafs, opts.include_leafs
+                        name, leaves, opts.include_leaves
                     ),  # pylint: disable=no-member
                     included_namespaces=included_namespaces,
                     included_ontologies=included_ontologies,
@@ -760,10 +761,10 @@ def _make_branchfig(  # pylint: disable=too-many-arguments,too-many-locals
         name: str,
         path: "Union[Path, str]",
         terminated: bool,
-        include_leafs: bool,
-        strict_leafs: bool,
+        include_leaves: bool,
+        strict_leaves: bool,
         width: float,
-        leafs: "Union[str, list[str]]",
+        leaves: "Union[str, list[str]]",
         relations: str,
         edgelabels: str,
         rankdir: str,
@@ -776,11 +777,12 @@ def _make_branchfig(  # pylint: disable=too-many-arguments,too-many-locals
         Args:
             name: name of branch root
             path: optional figure path name
-            include_leafs: whether to include leafs
-            strict_leafs: whether strictly exclude leafs descendants
+            include_leaves: whether to include leaves as end points
+                to the branch.
+            strict_leaves: whether to strictly exclude leave descendants
             terminated: whether the graph should be terminated at leaf nodes
             width: optional figure width
-            leafs: optional leafs node names for graph termination
+            leaves: optional leaf node names for graph termination
             relations: comma-separated list of relations to include
             edgelabels: whether to include edgelabels
             rankdir: graph direction (BT, TB, RL, LR)
@@ -790,19 +792,19 @@ def _make_branchfig(  # pylint: disable=too-many-arguments,too-many-locals
 
         Returns:
             filepath: path to generated figure
-            leafs: used list of leaf node names
+            leaves: used list of leaf node names
             width: actual figure width
 
         """
         onto = self.ontodoc.onto
-        if leafs:
-            if isinstance(leafs, str):
-                leafs = leafs.split(",")
+        if leaves:
+            if isinstance(leaves, str):
+                leaves = leaves.split(",")
         elif terminated:
-            leafs = set(self.get_branches())
-            leafs.discard(name)
+            leaves = set(self.get_branches())
+            leaves.discard(name)
         else:
-            leafs = None
+            leaves = None
         if path:
             figdir = os.path.dirname(path)
             formatext = os.path.splitext(path)[1]
@@ -821,9 +823,9 @@ def _make_branchfig(  # pylint: disable=too-many-arguments,too-many-locals
         graph = OntoGraph(onto, graph_attr={"rankdir": rankdir})
         graph.add_branch(
             root=name,
-            leafs=leafs,
-            include_leafs=include_leafs,
-            strict_leafs=strict_leafs,
+            leaves=leaves,
+            include_leaves=include_leaves,
+            strict_leaves=strict_leaves,
             relations=relations,
             edgelabels=edgelabels,
             included_namespaces=included_namespaces,
@@ -843,7 +845,7 @@ def _make_branchfig(  # pylint: disable=too-many-arguments,too-many-locals
         if not os.path.exists(destdir):
             os.makedirs(destdir)
         graph.save(filepath, fmt=fmt)
-        return filepath, leafs, width
+        return filepath, leaves, width
 
     def process_branchfigs(self):
         """Process all %BRANCHFIG directives."""
@@ -856,10 +858,10 @@ def process_branchfigs(self):
                     path="",
                     caption="",
                     terminated=1,
-                    include_leafs=1,
-                    strict_leafs=1,
+                    include_leaves=1,
+                    strict_leaves=1,
                     width=0,
-                    leafs="",
+                    leaves="",
                     relations="all",
                     edgelabels=0,
                     rankdir="BT",
@@ -883,10 +885,10 @@ def process_branchfigs(self):
                     name,
                     opts.path,  # pylint: disable=no-member
                     opts.terminated,  # pylint: disable=no-member
-                    opts.include_leafs,  # pylint: disable=no-member
-                    opts.strict_leafs,  # pylint: disable=no-member
+                    opts.include_leaves,  # pylint: disable=no-member
+                    opts.strict_leaves,  # pylint: disable=no-member
                     opts.width,  # pylint: disable=no-member
-                    opts.leafs,  # pylint: disable=no-member
+                    opts.leaves,  # pylint: disable=no-member
                     opts.relations,  # pylint: disable=no-member
                     opts.edgelabels,  # pylint: disable=no-member
                     opts.rankdir,  # pylint: disable=no-member
@@ -921,9 +923,9 @@ def process_branchdocs(self):  # pylint: disable=too-many-locals
                     title=title,
                     caption=title + ".",
                     terminated=1,
-                    strict_leafs=1,
+                    strict_leaves=1,
                     width=0,
-                    leafs="",
+                    leaves="",
                     relations="all",
                     edgelabels=0,
                     rankdir="BT",
@@ -943,15 +945,15 @@ def process_branchdocs(self):  # pylint: disable=too-many-locals
                     else ()  # pylint: disable=no-member
                 )
 
-                include_leafs = 1
-                filepath, leafs, width = self._make_branchfig(
+                include_leaves = 1
+                filepath, leaves, width = self._make_branchfig(
                     name,
                     opts.path,  # pylint: disable=no-member
                     opts.terminated,  # pylint: disable=no-member
-                    include_leafs,
-                    opts.strict_leafs,  # pylint: disable=no-member
+                    include_leaves,
+                    opts.strict_leaves,  # pylint: disable=no-member
                     opts.width,  # pylint: disable=no-member
-                    opts.leafs,  # pylint: disable=no-member
+                    opts.leaves,  # pylint: disable=no-member
                     opts.relations,  # pylint: disable=no-member
                     opts.edgelabels,  # pylint: disable=no-member
                     opts.rankdir,  # pylint: disable=no-member
@@ -972,9 +974,9 @@ def process_branchdocs(self):  # pylint: disable=too-many-locals
                     )
                 )
                 if with_branch:
-                    include_leafs = 0
+                    include_leaves = 0
                     branch = filter_classes(
-                        onto.get_branch(name, leafs, include_leafs),
+                        onto.get_branch(name, leaves, include_leaves),
                         included_namespaces=included_namespaces,
                         included_ontologies=included_ontologies,
                     )
@@ -1027,10 +1029,10 @@ def process_allfig(self):  # pylint: disable=too-many-locals
                     path="",
                     level=3,
                     terminated=0,
-                    include_leafs=1,
-                    strict_leafs=1,
+                    include_leaves=1,
+                    strict_leaves=1,
                     width=0,
-                    leafs="",
+                    leaves="",
                     relations="isA",
                     edgelabels=0,
                     rankdir="BT",
@@ -1071,10 +1073,10 @@ def process_allfig(self):  # pylint: disable=too-many-locals
                         name,
                         opts.path,  # pylint: disable=no-member
                         opts.terminated,  # pylint: disable=no-member
-                        opts.include_leafs,  # pylint: disable=no-member
-                        opts.strict_leafs,  # pylint: disable=no-member
+                        opts.include_leaves,  # pylint: disable=no-member
+                        opts.strict_leaves,  # pylint: disable=no-member
                         opts.width,  # pylint: disable=no-member
-                        opts.leafs,  # pylint: disable=no-member
+                        opts.leaves,  # pylint: disable=no-member
                         opts.relations,  # pylint: disable=no-member
                         opts.edgelabels,  # pylint: disable=no-member
                         opts.rankdir,  # pylint: disable=no-member
diff --git a/ontopy/ontology.py b/ontopy/ontology.py
index 54e379c04..a7f35262d 100644
--- a/ontopy/ontology.py
+++ b/ontopy/ontology.py
@@ -1221,25 +1221,25 @@ def get_annotations(self, entity):
     def get_branch(  # pylint: disable=too-many-arguments
         self,
         root,
-        leafs=(),
-        include_leafs=True,
-        strict_leafs=False,
+        leaves=(),
+        include_leaves=True,
+        strict_leaves=False,
         exclude=None,
         sort=False,
     ):
         """Returns a set with all direct and indirect subclasses of `root`.
-        Any subclass found in the sequence `leafs` will be included in
+        Any subclass found in the sequence `leaves` will be included in
         the returned list, but its subclasses will not.  The elements
-        of `leafs` may be ThingClass objects or labels.
+        of `leaves` may be ThingClass objects or labels.
 
-        Subclasses of any subclass found in the sequence `leafs` will
-        be excluded from the returned list, where the elements of `leafs`
+        Subclasses of any subclass found in the sequence `leaves` will
+        be excluded from the returned list, where the elements of `leaves`
         may be ThingClass objects or labels.
 
-        If `include_leafs` is true, the leafs are included in the returned
+        If `include_leaves` is true, the leaves are included in the returned
         list, otherwise they are not.
 
-        If `strict_leafs` is true, any descendant of a leaf will be excluded
+        If `strict_leaves` is true, any descendant of a leaf will be excluded
         in the returned set.
 
         If given, `exclude` may be a sequence of classes, including
@@ -1249,8 +1249,8 @@ def get_branch(  # pylint: disable=too-many-arguments
         will be returned instead of a set.
         """
 
-        def _branch(root, leafs):
-            if root not in leafs:
+        def _branch(root, leaves):
+            if root not in leaves:
                 branch = {
                     root,
                 }
@@ -1269,13 +1269,13 @@ def _branch(root, leafs):
                     # include it.  Requireing that the R should be a strict
                     # parent of A solves this.
                     if root in cls.get_parents(strict=True):
-                        branch.update(_branch(cls, leafs))
+                        branch.update(_branch(cls, leaves))
             else:
                 branch = (
                     {
                         root,
                     }
-                    if include_leafs
+                    if include_leaves
                     else set()
                 )
             return branch
@@ -1283,25 +1283,25 @@ def _branch(root, leafs):
         if isinstance(root, str):
             root = self.get_by_label(root)
 
-        leafs = set(
+        leaves = set(
             self.get_by_label(leaf) if isinstance(leaf, str) else leaf
-            for leaf in leafs
+            for leaf in leaves
         )
-        leafs.discard(root)
+        leaves.discard(root)
 
         if exclude:
             exclude = set(
                 self.get_by_label(e) if isinstance(e, str) else e
                 for e in exclude
             )
-            leafs.update(exclude)
+            leaves.update(exclude)
 
-        branch = _branch(root, leafs)
+        branch = _branch(root, leaves)
 
         # Exclude all descendants of any leaf
-        if strict_leafs:
+        if strict_leaves:
             descendants = root.descendants()
-            for leaf in leafs:
+            for leaf in leaves:
                 if leaf in descendants:
                     branch.difference_update(
                         leaf.descendants(include_self=False)
diff --git a/tests/ontopy_tests/test_graph.py b/tests/ontopy_tests/test_graph.py
index 3441eab22..74d972af1 100644
--- a/tests/ontopy_tests/test_graph.py
+++ b/tests/ontopy_tests/test_graph.py
@@ -92,7 +92,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
     graph = OntoGraph(
         emmo,
         emmo.hasPart,
-        leafs=("mereological", "semiotical", "causal"),
+        leaves=("mereological", "semiotical", "causal"),
     )
     graph.save(tmpdir / "hasPart.svg")
 
@@ -128,7 +128,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
     graph = OntoGraph(
         emmo,
         emmo.Quantity,
-        leafs=[emmo.DerivedQuantity, emmo.BaseQuantity, emmo.PhysicalConstant],
+        leaves=[emmo.DerivedQuantity, emmo.BaseQuantity, emmo.PhysicalConstant],
         relations="all",
         edgelabels=None,
         addnodes=True,
@@ -145,17 +145,17 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
     graph.save(tmpdir / "legend.png")
 
     graph = OntoGraph(
-        emmo, emmo.EMMO, leafs=[emmo.Perspective, emmo.Elementary]
+        emmo, emmo.EMMO, leaves=[emmo.Perspective, emmo.Elementary]
     )
     graph.save(tmpdir / "top.png")
 
-    leafs = set()
+    leaves = set()
     for s in emmo.Perspective.subclasses():
-        leafs.update(s.subclasses())
-    graph = OntoGraph(emmo, emmo.Perspective, leafs=leafs, parents=1)
+        leaves.update(s.subclasses())
+    graph = OntoGraph(emmo, emmo.Perspective, leaves=leaves, parents=1)
     graph.save(tmpdir / "Perspectives.png")
 
-    leafs = {
+    leaves = {
         emmo.Interpreter,
         emmo.Conventional,
         emmo.Icon,
@@ -169,7 +169,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
         emmo.Engineered,
         emmo.PhysicalPhenomenon,
     }
-    semiotic = emmo.get_branch(emmo.Holistic, leafs=leafs.union(hidden))
+    semiotic = emmo.get_branch(emmo.Holistic, leaves=leaves.union(hidden))
     semiotic.difference_update(hidden)
     graph = OntoGraph(emmo)
     graph.add_entities(semiotic, relations="all", edgelabels=False)
@@ -182,7 +182,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
     legend.save(tmpdir / "Semiotic-legend.png")
 
     # Measurement
-    leafs = {emmo.Object}
+    leaves = {emmo.Object}
 
     hidden = {
         emmo.SIUnitSymbol,
@@ -202,7 +202,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
         emmo.Theory,
         emmo.Variable,
     }
-    semiotic = emmo.get_branch(emmo.Holistic, leafs=leafs.union(hidden))
+    semiotic = emmo.get_branch(emmo.Holistic, leaves=leaves.union(hidden))
     semiotic.difference_update(hidden)
     graph = OntoGraph(emmo)
     graph.add_entities(semiotic, relations="all", edgelabels=False)
@@ -215,7 +215,7 @@ def test_emmo_graphs(emmo: "Ontology", tmpdir: "Path") -> None:
         emmo.Reductionistic,
         relations="all",
         addnodes=False,
-        leafs=[
+        leaves=[
             emmo.Quantity,
             emmo.String,
             emmo.PrefixedUnit,
diff --git a/tools/ontograph b/tools/ontograph
index acc185222..874cb6f84 100755
--- a/tools/ontograph
+++ b/tools/ontograph
@@ -20,6 +20,7 @@ from ontopy.graph import (  # pylint: disable=import-error
     _default_style,
 )
 from ontopy.utils import get_label  # pylint: disable=import-error
+import warnings
 import owlready2
 
 
@@ -113,14 +114,20 @@ def main(
         help="Name of root node in the graph. Defaults to all classes.",
     )
     parser.add_argument(
-        "--leafs",
+        "--leaves",
         action="append",
         default=[],
         help=(
-            "Leafs nodes for plotting sub-graphs. May be provided as a "
-            "comma-separated string and/or with multiple --leafs options."
+            "Leaf nodes for plotting sub-graphs. May be provided as a "
+            "comma-separated string and/or with multiple --leaves options."
         ),
     )
+    parser.add_argument(
+        "--leafs",
+        action="append",
+        default=[],
+        help=("This argument is deprecated, please use `--leaves` instead"),
+    )
     parser.add_argument(
         "--exclude",
         "-E",
@@ -209,6 +216,14 @@ def main(
     )
     args = parser.parse_args(args=argv)
 
+    if args.leafs:
+        warnings.warn(
+            "The `--leafs` option is deprecated and will soon be removed. "
+            "Please use `--leaves` instead.",
+            DeprecationWarning,
+        )
+        args.leaves = args.leafs
+
     # Append to onto_path
     for paths in args.path:
         for path in paths.split(","):
@@ -229,13 +244,13 @@ def main(
         with open(args.generate_style_file, "wt") as handle:
             json.dump(style, handle, indent=4)
 
-    # Join all --leafs options
-    leafs = set()
-    for leaf in args.leafs:
+    # Join all --leaves options
+    leaves = set()
+    for leaf in args.leaves:
         if "," in leaf:
-            leafs.update(leaf.split(","))
+            leaves.update(leaf.split(","))
         else:
-            leafs.add(leaf)
+            leaves.add(leaf)
 
     # Join all --exclude options
     exclude = set()
@@ -298,7 +313,7 @@ def main(
         graph = OntoGraph(onto, style=style)
         graph.add_branch(
             root=root,
-            leafs=leafs,
+            leaves=leaves,
             exclude=exclude,
             relations=relations,
             edgelabels=args.edgelabels,