1.(adj) Used to describe something that is so awesome it
blows your mind. Comes from the fact that
ninjas are well..ninja.
2.Can also be used as a characteristic to describe a person or
thing.
1. "Did you see those gangstas on scooters rockin there
kickass skillz before??" "Yeah, it was so ninja!"
2. "That girl is so ninja for starting the use of the word ninja in many
people's daily life.
3. Daybies think that's so endo when really it's not
even ninja.