Navigation
Letter NSet of paths for moving through a structure: global, local, and contextual. It traverses IA; it does not replace it.
Updated:
Working definition
Navigation is the set of paths for moving through a structure: global, local, and contextual.
It is not Information Architecture. IA decides what exists and how it relates; navigation lets people move. A sitemap can represent that structure; a menu is one way to traverse it.