The act of making a fist and tapping it against your friends in a parting jesture or greeting. Abriviation for 'knuckles'
safe, knux bruv taps fist to other persons fist
form of recognition; aknowledgement, respect; major props.
Boy 1: So what did you do last night?
Boy 2: Oh, nothing..
Boy 1: Seriously, what did you do?
Boy 2: Let's just say I didn't get much sleep last night..
Boy 1: KNUX!!