similar in context to the phrase "Nah mate" meaning "no, thankyou" or simply "no." Quite often accompanied by a gesticulation involving the waving of hands on a horizontal plane, one above the other.
Yo mf lets go see Borat at the pictodrome!
Nash, its bare weak, seen it bare times. N ting.
Brrrap. Innit Check dis.
Nash, when will you get you some ezhucation.
When yo mama leaves the house!!!!!