piston 

Penis

He has a long piston

piston by toxicvic February 9, 2019

Piston 

Double penetration sex, with one man fucking the girl in her vagina in and the other in the ass. They alternate thrusts to create a piston action, much like that of an engine.

"You take her in the ass, I'll take her in the pussy and we'll piston her"

Piston by Color Rot January 6, 2009

Piston 

A Sexual act similar to cave diving. The male not only sticks his head in the woman's vagina, but proceeds to climb entirely inside of her. Once inside of her he sticks his penis out of her vagina. Using his penis the girl goes and engages in intercourse with someone else. (The only downfall to this act is that a cesarean section will need to be performed in order for the guy to come out.)

Friend 1: Did you hear about Jessica?

Friend 2:No what happened?

Friend1: Her and Jack did the piston!

Piston by The Pistonator September 3, 2014

piston 

someone who is an idiot

you're a complete piston

piston by mandy April 2, 2004

piston 

somebody who is sh** ugly

Eww you like him he a piston.

piston by Jada I December 15, 2006

piston 

a long hard metal pole that i rammed in and out of an explosion chamber, used too create energgy annd poduces a loud sound

the pistons of an engine

piston by wastedcoworgasm February 20, 2024

Piston-hands 

Moniker for a jagged toothed female who coerces men into receiving unabashed, violent handjobs as a way of validating her morbid existence.

Look at Piston-hands talking to those guys; that hook nosed bitch is about to do something they will regret.

Piston-hands by urbanjerk July 14, 2010