the gayest thing a person can do in a moshpit. the "art" of ninjacore is basically doing ninja-like moves, such as spin kicks and spinning fists in an effort to make space for themselves in the pit. looks as gay as it is.
dude, this ninjacore kid started punching me in the trivium moshpit last friday so i knocked the cunt out!
A form of the word Ninja Yes.
"Dude, that's a sweet bike."
"Yeah, totally ninjacore."