1. A word used to describe a woman's rear-end that is particularly flat, unpleasing or unattractive to look at, as opposed to the regularly used "donk".
2. The term refers to the relationship between two Disney characters, one being a donkey and the other being an unattractive ogre. The donkey or "donk" being the preferred choice of rounded, plump rear end, and the "shrek" term referring to it's polar opposite, flat rear end.
A green over weighted man who lives in a swamp who hates humans and acts like a retard in front of everybody and has a pet Donkey who talks crap and talks nonsense to Shrek and his friends. He is also a giant fat man is a green suit.