This word is traditionally used in an urban setting. Swearing that something is true. An affirmation of the validity of a questionable statement or factoid. Originated from 'swearing on ones dead nephews.
person A: she gave me brain.
person B: naw dawg, you ain't a playa like that.
person A: yo! on the nephs bitch hooked it!
school full of girls who are amazing at just about everything. foxcroft girls are just jealous and say so much shit about madeira girls bc they wish they could be one.
foxcroft girl: god i wish i was at madeira. they rejected me so i had to come here.