Not to be confused with the abbreviated form of nitrous oxide, this noun/adjective, is used to convey the message that something is "nice" when its really kind of dumb, accentuating the word nice in order to put down an individual
Depending upon the situation one may also say nos in a positive way
Billy: Hey, do you guys want to come to see the backstreet boys live for my birthday
Sam: Billy, YOU'RE NOS
Chris: Dude, i just had the best sluuushie ever!