Add :term:s for descriptors.
diff --git a/Doc/library/_ast.rst b/Doc/library/_ast.rst
index 9b195be..9383591 100644
--- a/Doc/library/_ast.rst
+++ b/Doc/library/_ast.rst
@@ -14,7 +14,7 @@
The ``_ast`` module helps Python applications to process trees of the Python
abstract syntax grammar. The Python compiler currently provides read-only access
to such trees, meaning that applications can only create a tree for a given
-piece of Python source code; generating byte code from a (potentially modified)
+piece of Python source code; generating :term:`bytecode` from a (potentially modified)
tree is not supported. The abstract syntax itself might change with each Python
release; this module helps to find out programmatically what the current grammar
looks like.