look up any word, like b4nny:
 
1.
A smug and superior advocate of steampunk culture. Douchebag of a bygone era.
That guy in the bowler hat and handlebar moustache says he can go home with any girl in this bar. What a steambag!
by fling! June 23, 2011
 
2.
Verb: is similar to a T Bag however, a Steam Bag is the act of placing ones testicles over the eyes of another person and then farting in that persons mouth.

a. an unconscious, drunk guy.
b. an unconscious, drunk chick.

The term Steam Bag originates from the Delta Fu Gamma - Phoenix, AZ chapter.
Dude, Nick passed out drunk last night with his mouth wide open so, I gave him a Steam Bag!

by Dance Commander December 16, 2007
 
3.
To defecate into a small plastic baggie, tie the bag shut with rope or string, and twirl it in circles hitting your friend in the face several times. Usually done in a jovial or festive manner.
After Jill announced she was pregnant, all her friends playfully steambagged her until everyone was exhausted and covered with corn niblets.
by Mr. Snap November 01, 2009