A large, human-like bird, usually bald, who lives in the northern Massachusetts area and squaks loudly while flapping his arms. Wears a funny hat and is obsessed with toilets.
"Did you hear that? What the hell was that?"
"Oh, just the McCarter Bird."
This is where a man is at the bar buying a woman drinks and another man swoops in and takes the drunk woman home for sex without spending a single dollar. While pulling a dirty bird one could add insult to injury by doing the infamous Atlanta Falcons Dirty Bird dance to celebrate.
If you are out at the bar and notice a dirty bird type woman accepting free drinks from another man, one could swoop in and pull a dirty bird on the dirty bird.