Someone who writes Urban Dictionary definitions about themselves, or people who they know, but who are not famous. Esp. when those definition is "*insert name here* is very cool and attractive."
Person 1: Hey! Jeremiah defined himself on Urban Dictionary!
Person 2: What an Urban Dictionary Dumbass...
A person who gives a dumbass definition for something on urban dictionary
Hey I wonder what ascot means Ill search it on urban dictionary. Ascot : slang for yo ass got bigger. Wtf a real urban dictionary definition would be that thing Fred wears around his neck on scooby doo wow this guy is an urban dictionary dumbass