A menu in UD that most people don't even know exists. It's located on the top left, just above the add a definition option. This option is really crappy to use on your phone because it doesn't show you the whole alphabet. Not to mention, it sucks to use because most letters have at least 1000 pages and you can only move two page at a time, or go straight to the end.
The browse menu on Urban Dictionary can show you a lot of weird definitions, but only if you're patient enough to flip through the pages.