The mechanism in your brain that allows you to "play" songs in your head. Differs from an earworm in that the headpod is voluntary and plays songs that you like.
adj: a beat or rhythm that is hypnotic to the point of making your head nod. Believed to be pioneered, but not created by, Pandora radio as an attribute of music, specifically in hip-hop, hip-hop instrumentals and trip-hop genres.
The involuntary and repetitive head reflex one exercises when listening to a really tight jam (song). The individual bobs his/her head to the beat of the jam, exuding a feeling of confidence and coolness that quickly vanishes once the jam ends.
Once "Nothin' But A G Thing" came on the speakers, Maleeq's headnod intensified dramatically and the hos noticed his good vibe.
Performing fellatio to such a skillful extent that air is sucked out of the room, decreasing the partial pressure of oxygen until the receiving partner succ-umbs to hypoxia.
I gotta stop seeing Katie you guys, we hooked uplast night and she gave me headpoxia, I almost fucking died.