A small catapult designed to fire at crotch level, thus insuring maximum damage and maximum hilarity. Used just as often for pranking as it is for self defense.
Remember crotchapult is for self-dense or self-amusement only. Do not use a crotchapult to commit crimes or use on pets, small children, or women without a sense of humor.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"