Someone who is obsessed with RENT. They know every word to every song, have seen BOTH the movie and the play, and love it to death. They know every little detail, from the fact that 'Take Me Or Leave Me' was added two rehearsals before show time, to the precise differences between the Movie and Stage show.
Forrest is such a RENThead, He knows all the words, facts, and little everythings about RENT.
RENTheads, gosh, get a life, RENT isn't something to obsess about. Just because YOU know everything about it, doesn't mean we do.