short for "model-actor" - the people who live in Los Angeles trying to make it as a model-actor-whatever and appear on many reality tv shows...see also "attention whore"
Check out the new cast of Survivor, half of them are mactors this year.
by ftwftw July 17, 2006
An adjective used to describe a female that pleasantly plump. Comes from a combination of the word mush and the word factor.
That girl used to be athletic, but when she quit working out, the mactor took over.
by dirtydog420 January 23, 2012