Goal: Nail down UI and other WordPress terminology.
Method: I'd be a pain to talk back and forth on wp-docs for this, I think. Instead, add something here that you feel needs a standardized name. Offer some suggestions and vote by adding your 'three-tilde' signature to the appropriate line. Naturally, your opinion may shift with time and when new suggestions get made. Feel free to change your vote.
Also: See cAse.
This article is never meant to go live. The idea is to figure out what to call things and then call them that in the Glossary and elsewhere in Codex.
The Entire Interface - everything you see at wp-admin/
The Menu - The white bar in the Admin Interface with 'Dashboard' through 'Logout ()'
The Menu Items - 'Dashboard' 'Options' etc.
The Submenus - The gray bar below the Menu. At Write, it displays 'Write Post' 'Write Page'.
The Submenu Items - 'Write Post' 'Write Page'
The Pages Themselves - What you see when you click a Menu or Submenu Item.
Definition of 'Tag'
<?php ... ?>
Definition of 'Function'