As a noun, a duckoff is a person that is always reliable for sex. As a verb, it means to have sex. It comes from Greensboro, NC and is most commonly used by Eastside Gator Crips.
boy: Who is that girl?
boy 2: that's my duckoff.
boy: Where are you going man?
boy 2: I'm bouts to go duckoff.
a rude way to address a young female. Like saying trick or hoe.
boy: look at that breezy!
boy 2: I know, she is fine!!!