A REALLY ugly motorcycle that is ridden often, never cleaned, and maintained at the absolute minimum for it to run. Some rat bikes are built from scrap parts (often from 4 or 5 different motorcycle brands), others start off as nice bikes and gradually become rats. They are often spray-painted camo or matte black to cover all the rust.
I picked up a rat bike at a redneck garage sale for 50 bucks.
January 03, 2005