Add a glossary entry for file objects.
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index fc64b84..ac94ef2 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -781,9 +781,9 @@
single: stdout (in module sys)
single: stderr (in module sys)
- A file object represents an open file. Various shortcuts are available
- to create file objects: the :func:`open` built-in function, and also
- :func:`os.popen`, :func:`os.fdopen`, and the :meth:`makefile` method
+ A :term:`file object` represents an open file. Various shortcuts are
+ available to create file objects: the :func:`open` built-in function, and
+ also :func:`os.popen`, :func:`os.fdopen`, and the :meth:`makefile` method
of socket objects (and perhaps by other functions or methods provided
by extension modules).