Meaning
What does Knuck if you Buck mean?
Knuck if you buck is a colloquial expression taken from the hit of the crunk band Crime Mob.
The expression could be extended as “knuckle up if you’re buck wild” which can be interpreted as “get ready to fight if you’re acting aggressive”.
Thus, “knuck if you buck” is a challenge to a fistfight
Origin
What's the origin of Knuck if you Buck?
The expression comes from the title of Crime Mob’s single, released on June 29th, 2004, for their debut album, titled Crime Mob.
The song received a good reception, becoming a hit in Atlanta, and a signature crunk track.
Spread & Usage
How did Knuck if you Buck spread?
It was first defined on Urban Dictionary in 2004.
“Knuck if you buck” remains a popular song, as well as a popular way of challenging someone to a brawl.

External resources
- Complex.com – 5 Things You Didn’t Know About “Knuck If You Buck”
- Gimletmedia.com – An Oral History of Knuck If You Buck