a whack mc is usually any rapper on Mtv... these people rap to make money and talk about nothing exept thier money and hot ass girls in the videos, thease people are NOT to be confused with hip-hop artists. real hip-hop M.C.'s rap about life, and all aspects of it.
lil'jon is a whack m.c. what a dumb ass? why did you people make him a millionare?
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?"