To blow the smoke from a joint from one persons mouth into anothers.
by Anonymous March 13, 2003
(noun) In a convertible it's the (somewhat surprising) way the air blows from the back of the car toward the front. Many convertible drivers wear hats to reduce the effects of blow back. Fancy convertible makes such as Mercedes, BMW and Porsche often mount a screen behind the car's front seats to reduce blow back to those passengers.
Red thought he was all cool in his convertible until the blow back pushed his cap over his eyes and he ran down that mailbox.
by b1-66er April 29, 2008
When you fart into a cushioned chair or seat, get up for something and then sit down again, only to have your weight cause the cushion to blow the offensive odor back into your face.
Geez, I gotta get a leather chair. I'm tired of irksome fart blow backs everytime I sit down after lunch.
by Beatnik57 October 24, 2007
1.When your IQ is so low that your penis turns on you and it attempts to rip it self from your retarded body by backfiring.

2.Penil suicide...if yours does this that means you should to!!!!
Gary:Holy wheres my cock?!?!?!
Stevy: Dude blow back
Mary:Whos cock just landed in my lemonade?!
by John May 7, 2004
When you're getting a blowjob and you're on the verge of cumming the girl or guy blows the cum back up your cock.
Blow back: The stupid whore blew the cum back up my cock so I gave her a strawberry cheese cake. That'll teach the bitch!!!!!!!!!!!!
by Paedobear August 7, 2006
When your girlfriend gives you a blow job at home so hard that cum shoots out so fast that it starts to blow you girlfriend back 10 feet and covers your house.
we were doing it so hard it started blowing back at her 10 feet
by rshizzal February 2, 2015
When urinating after a night of sexy times your cheese helmut redirects your stream back to your pants leg.
Girl: What the #&%$? Why are you pissing in the sink?!
Me: Rather pee in the sink than get BLOW BACK on my pants.
by Mike Hawk Fitzwell August 31, 2009