Add a glossary entry for file objects.
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index e3c9723..c061b04 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -617,7 +617,7 @@
.. index:: single: I/O control; buffering
- Return a :dfn:`file object` associated with the socket. The exact
+ Return a :term:`file object` associated with the socket. The exact
returned type depends on the arguments given to :meth:`makefile`. These
arguments are interpreted the same way as by the built-in :func:`open`
function.