1. A "new member" of a fraternity who is nothing more but a dirty pledge therefore he is referred to accordingly.
2. A derogatory term used by brothers of a frat to belittle their pledges.
Nick: I'm so happy to have joined this fraternity, it's the best on campus. I'm so excited to have fun.
Rod: Shut your mouth you stupid Pledge Fuck, and drop and give me ten push-ups!!!
Nick: Push-Ups I can only do 5....
Rod: Then chug this beer PledgeFuck!!!