Masterchillin 

masturbating while doing something else (such as playing video games, watching regular t.v., or im-ing)

i was totally masterchillin in that halo game last night!

Masterchillin by john bowendil March 17, 2008

mastercalling 

calling someone while materbaiting and saying u have to go when about to orgasim

i was mastercalling my mom from my room

mastercalling by athony--->smosh October 1, 2011

Masterchiefing 

Verb; When one breaks up his or her weed on the case of any game in the Halo series. i.e. Halo, Halo 2, Halo 3, etc.

DOOOOOOODE, we totally broke up some DANK ASS SHIT on Halo 3 last night and we were Masterchiefing the fuck out of it!

Masterchiefing by BITTERwork May 14, 2011