Noun: Someone who masturbates. A person who vigorously strokes their penis with their hand or other implement.
Verb: To masturbate. A play on words, like when you cock a gun, except you are cocking your cock.
Person 1: Man, I need to stop masturbating
Person 2: Dude, you're such a cocking cock.
Person 1: Dude! Stop cocking your cock in my room!
Person 2: I can't help it! I'm such a cocking cock!