Verb. A "Bear Trap" is performed when one guy walks up to his friend, and, instead of conventionally punching his friend in the nuts, surprises him by clenching onto one's testicles and twisting and crushing said gonads. -WARNING: Considered VERY painful, somewhat homosexual, and highly unsuggested to be performed upon chicks. Yeah... bad idea.
"I made a bet with my friend Josh, and he has two days to pay me back that 5 spot I loaned him or I get to bear trap the holy f#$%ing Jesus out of him... unresisted! Sweet!"-Me