1 definition by MPleitch
The horrible perspiration that comes from prolonged trips in a car. The back sweat is the worst and most nerve-racking part about going on a date, because when you go to hug your date, you pray to God that she doesn't feel the damp rag that is the back of your shirt. Most prominent in summer. Cure-unknown
Well, she dumped me. Probably because I had horrible back sweat after driving all the way to her house!
by MPleitch January 13, 2006