something obviously false, something fake (from the fact that there are no three dollar bills)
This jewel is a 3 dollar bill.
by The Return of Light Joker February 18, 2009
1 more definition
something that is very queer;involving gayness
Dude that teacher givin us that homework is as gay as a 3 dollar bill!
by Cory Barker April 28, 2007