1 definition by Clam Choder

Backjack

A form of masturbation where you slide your hand down your dick with your hand backwards, forefinger and thumb touching eachother. Your thumb should be facing in twards your balls and your pinky out twards the head.
Painting a face on your hand is optional.

"Sometimes I rub one out backjack style to shake things up a bit."

by Clam Choder April 25, 2007