Using small residential side streets during a commute, resembling the route a rat would take in a maze. Growing in use since the invention of Waze and other commuting apps.
Dave's commute had become awful due to the new development, so he decided to rat run, saving a few minutes off his drive.
by Graybeard88 April 10, 2017
by OI LOVE, GET YER RAT OUT! July 25, 2006