diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index 1ab8a8c0b46..fb5c01868c9 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -69,7 +69,7 @@ Glossary
       it's almost certain you can safely ignore them.
     
    context manager
-      Objects which control the environment seen in a :keyword:`with`
+      An objects that controls the environment seen in a :keyword:`with`
       statement by defining :meth:`__enter__` and :meth:`__exit__` methods.
       See :pep:`343`.