1.) To give fellatio until one is to run dry of semen.
2.) Used interjectionally without knowing the meaning by the mind-controlling alien in Aqua Teen Hunger Force after he learned it from one of Carls talk-nasty tapes. Then later said at his own will after a job interview.
interviewer: Okay, well when we start hiring.. animals or whatever.. we'll give you a call.
alien: suck it dry!