a tweaker is someone who has been doing Crystal Meth for a while and feens for it and is always twitching. Some one who is an addict for Meth.
L. - damn nigga YU're girl is a tweaker aint she?
P. - Ya im going to drop that bitch soon, she fucking up and be doing too much for the dopey
L. - oh, yah how much, give her my number in that case.