+ "context manager"
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index c834743..1ab8a8c 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -68,6 +68,11 @@
advanced mathematical feature. If you're not aware of a need for them,
it's almost certain you can safely ignore them.
+ context manager
+ Objects which control the environment seen in a :keyword:`with`
+ statement by defining :meth:`__enter__` and :meth:`__exit__` methods.
+ See :pep:`343`.
+
decorator
A function returning another function, usually applied as a function
transformation using the ``@wrapper`` syntax. Common examples for