look up any word, like oprah dollars:
 
2.
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
 
1.
A man's worse nightmare. While frequent in driving, it can often occurs spontaeously when temperatures are above 58 degrees Fahrenheit. Basically from March to October you pray that no girl accidently brushes against your back and feels your moist lumbar. Likewise wearing t-shirts that clearly show your back sweat is also not advised.
"Hey man it's suppose to reach 60 today!"
"Oh crap man, back sweat is coming, i can feel it."
by Keith B. May 11, 2006