BigMAC (verb) the act of masturbating in front of your Mac laptop until you reach climax, and then slamming the Mac book laptop closed on top of your penis while ejaculating. Also referred to as the "MACaroni n Jizz."
I just Big MAC'd to that Chyna sex tape, I think I broke my laptop, also my dick hurts super bad.
Big Mac is when you crap in the toilet (or not) and you feel like you've accomplished your duty and wipe. Then you have overwhelming urge to sit and crap again. Landing that turd on top of the toilet paper which is sitting directly on top of your previous turd.