An adjective describing a disheveled, ugly, homeless or generally unpleasant looking person, dog or other animal. It is derived from a Mexican comedy show in which a character by the name of Chimoltrufia, a chambermaid, displayed this unappealing look in each of her sketches.
Person 1: Look at that dog running around on the beach looking all chimu.
Person 2: Man, if I didn't know any better, I'd say that dog was either homeless or just born with bad luck!
A twitter user who uses the hashtag for any purpose, but typically to develop a topic of their own making into a meme or to self-promote.
The hashers were out in force when moonfruit was offering a free laptop to people who included the tag "#moonfruit" in their tweet, resulting in a lot of positive PR for them.