It is slang for a girl or hoochie who likes to sleep around with many partners. She is known as a tramp and also used and bounced on much like a trampoline you buy at the store.
(sentence): "I'm feeling horney... lets go to club and find us some trampolines."
(v.) the act of holding a shirt over ones genitals whilst whipping one's hips and external genitalia in the direction of said shirt, thereby creating the effect in the shirt that is seen on the underside of a trampoline when teenagers jump on it
Jeph, in a celebratory action, pulled down his pants, held his Chrebet jersey taught over his genitalia, trampolining it in front of everyone watching the game.
By Malinde
Trampolining
Something that SNL made up: Boys sit on a one story roof, while a girl jumps up and down on a trampoline and gives him head while she's in the air. When a girl has trampolined 10 guys, she gets a Silly band
did you see SNL last night, with the skit with the trampolining and souping? we should do that