To save the co-workers and the clients from confusion a common language to describe the elements of the web site is a good idea I think. I've seen a couple of design pattern sites but I wonder if someone could point me to a dictionary somewhere in the world wide web that describes common elements such as primary navigation, header, footer, utility menus snipplets etc etc.
I couldn't find one that had everything. I found 4 that in combination should cover the majority of web design jargon.
Web Design Glossary by University of Minnesota Duluth
Web Design Glossary from About.com
The Motive Web Design Glossary
Glossary of Graphic Design and Web Page Design Terms by Grantastic Designs (some terms are illustrated)