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2.
a phrase uttered in encouragement meaning: "muster your courage, intestinal fortitude and love for the American-way in preparation for an upcoming (or admist a) challenge
of epic proportions!"
(uttered many times by one of the dudes in the movie "The Matrixs:Revolutions" during battle
against the electro-mechanical foe)
"Here they come boys ... Knuckle up!"
by abc July 13, 2004
91 34
 
1.
To prepare to kick another's ass, getting prepared to engage in fisticuffs
If you get up in my grille, you best knuckle up, motherfucker
by stefanali pops September 13, 2005
319 86
 
3.
to prepare to fight.
Guy 1 "i was at the bar chillin talkin to this girl after the band played, then this dude looked at me like he wanted a problem."

Guy 2 "what happened?"

Guy 1 "I had to knuckle up then his boy pulled him back."
by J Fri May 11, 2008
21 9
 
4.
TO Put Up YOUR Setz And get ready to fight
Knuckle up nucker
by shane June 18, 2003
51 40
 
5.
To Make Reddy, To Make Preparation, To Assemble, To Focus on the objective, To concentrate
Tomorrow's the big day people, there's no room for mistakes, so all of you better Knuckle-Up!
by ElkarO November 05, 2003
8 2
 
6.
An action akin to the high-five or the handshake. The act of touching fists knukle-to-knuckle in greeting or departure. In 2003 this action was accompanied by the phrase "knuckle-up" but has since just become the motion without the phrase. The first instance of this action and phrase was in Dallas, TX in the mid-90's and has since become a common gesture in most public forms of transit in NYC.
Jimbo-- "Is that some kind of a gang sign?"
Miguel--"Nah, that's a knuckle-up, bro."
by super steve August 30, 2005
4 9
 
7.
To masturbate
The act of masturbation
Guy 1: Did you see Stacey?

Guy 2: Yeah, total nipple slip! I'm totally going to knuckle up to that later
by leobaby1 November 18, 2011
2 11