The act of being a ninja or doing ninja related things, such as jumping building, running with your hands loosely behind you, or climbing up trees and hiding until your "Target" approaches.
He displayed his awesome Ninjaness when he jumped from that K-mart to the Subway.
Brian the Ninja가 작성 2006년 12월 19일 (화)
The amount of inner ninja possessed by an individual.
That guy has so much ninjaness hes almost like Chuck Noris
w00000000000t가 작성 2005년 12월 20일 (화)