beefneck
reaction to when someone says something stupid, you slap them on the back of the neck while saying "beefneck"
Person #1: "Megan Fox isn't hot"
Person #2: "Beefneck"
Person #2: "Beefneck"
Beefneck
When someone says a gay joke, something stupid, or something that deserves to be punished for. You also say beefneck while slapping the back part of their neck. Beefneck is a way to say that something is dumb; some people confess and put forward their necks and get hit, voluntarily.
Jimmy: Basketball is one of the dumbest sports ever.
John: Beefneck!!
(Slaps back of neck)
John: Beefneck!!
(Slaps back of neck)