1. headbump - Noun
2. headbump - Verb
A light nudge or bump done with the head as an affectionate gesture, typically by an animal.
A naturally-occurring bump on the cranium, especially as analyzed in phrenology.
headbump (third-person singular simple present headbumps, present participle headbumping, simple past and past participle headbumped)
(especially of an animal) To nudge or bump with the head as a gesture.