Short for master of ceremonies or mic controller. Essentially a word for a rapper but the term is not limited to hip hop. Drum and Bass, Garage, Happy Hardcore, Ragga and old school rave all feature MCs, however with these genres, the MC generally MCs live while a DJ mixes the tunes, whereas hip hop MCs mainly do so on record
Navigator is a wicked MC
Biggie was a phat MC
I'm MCing at a house party tonight, you coming?