A tradition in rural America, and the unisex term for a fish bump. (which refers specifically to vagina-equipped humans)
It's like a chest bump but at crotch level. It is not typically a sexually charged or intimate event.
Its romantic counterpart is referred to as a chicken kiss.
After throwing down a baller alley-oop, I chicken bumped my youth pastor. He almost got arrested but I told the cops that it wasn't a weird sex thing.
A Japanese alternative rock group consisting of Motoo Fujiwara (Vocalist/guitarist), Yoshifumi Naoi (bassist), Hiroaki Masukawa (lead guitarist) & Hideo Masu (Drummer)