A word made by combining the words "head" and "drop" to describe the action of dropping one's own head in response to a sarcastic remark.
John: Paris Hilton is fat, Kanye West has terrible lyrics, Lil Wayne's flow is terrible, Lady Gaga isn't weird at all, Justin Bieber has a low voice, and Birdman never talks about money.
A "head drop" is a motion made when one is listening to pleasing music that makes that person bobble their head.
Another form of headbanging, usually to slower forms of music.
Ah, shit, I'm feeling this beat; I can't even control this head drop!
The motion of suddenly lowering oneself's head in response to a sarcastic remark. In text, it is conventionally set off with asterisks.
Joey: Dude, Birdman never raps about expensive cars and money.