diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index ca8af56f2da..e2c0b6d17d9 100644
--- a/Doc/library/ast.rst
+++ b/Doc/library/ast.rst
@@ -110,9 +110,9 @@ The abstract grammar is currently defined as follows:
 Apart from the node classes, :mod:`ast` module defines these utility functions
 and classes for traversing abstract syntax trees:
 
-.. function:: parse(expr, filename='<unknown>', mode='exec')
+.. function:: parse(source, filename='<unknown>', mode='exec')
 
-   Parse an expression into an AST node.  Equivalent to ``compile(expr,
+   Parse the source into an AST node.  Equivalent to ``compile(source,
    filename, mode, ast.PyCF_ONLY_AST)``.
 
 
diff --git a/Lib/ast.py b/Lib/ast.py
index ba880c93ec0..72237ed9085 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -28,12 +28,12 @@ from _ast import *
 from _ast import __version__
 
 
-def parse(expr, filename='<unknown>', mode='exec'):
+def parse(source, filename='<unknown>', mode='exec'):
     """
-    Parse an expression into an AST node.
-    Equivalent to compile(expr, filename, mode, PyCF_ONLY_AST).
+    Parse the source into an AST node.
+    Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
     """
-    return compile(expr, filename, mode, PyCF_ONLY_AST)
+    return compile(source, filename, mode, PyCF_ONLY_AST)
 
 
 def literal_eval(node_or_string):