look up any word, like half chub:
 
1.
1. A person that is equal in your esteem to a lump of feces

2. A lump of feces
In the Pilot Episode of Firefly (aired last by the same backbirths that cancelled it after less than a season) the "Purplebelly" Federal Agent sometimes called the "Mole" says, “Do you think I am a complete back birth?”
by —thoughtstorms— March 26, 2009
 
2.
A colorful term meaning approximately "hick", "idiot", or "stupid person".
"You think I'm a complete backbirth?"
"He’s a total backbirth."
by Bob Aman June 16, 2008
 
3.
(n.) A pejorative whose recipient the utterer believes to have been born through his mother's anus; an assbaby. May be applied equally to those who exhibit stupid, sociopathic, or otherwise fecal behavior.
"Do you think I'm a total backbirth?"
"Dude, quit being such a damn backbirth!"
by BoxOfSigns February 14, 2010