To challenge someone by getting in their face and disrespecting them with belligerent comments or trying to stare the them down.
I was laughing at this guy behind this one dude and the dude thought I was laughing at him so this nigga had the nerve to BUCK UP to me and I had to lay his ass down.
by Joshiro007 February 12, 2003
 Get the BUCK UPmug.
Get the BUCK UPmug. by Raging Fish February 8, 2009
 Get the Buck Toothmug.
Get the Buck Toothmug. A low class establishment advertised as the county's premier gentlemen's club in eastern Pennsylvania. Your hopes are high, but when you walk in the door, the first thing on your mind is, "Good lord, at least it's BYOB!" The smell of cesarean sections, and asshole fill the air. You immediately call the doctor for an STD checkup Monday morning. Even though we all know how 'classy' of a titty bar Buck Rubs actually is, we still find ourselves sitting there quite frequently tossing singles at the dregs of society.
Bob: "Hey man, wanna go to Buck Rubs?"
Neil: "Nah I'm good, I already had the clap once this month."
Neil: "Nah I'm good, I already had the clap once this month."
by Quecumber January 5, 2012
 Get the Buck Rubsmug.
Get the Buck Rubsmug. by Josh November 28, 2004
 Get the Young Buckmug.
Get the Young Buckmug. by anonymous June 8, 2004
 Get the big buckmug.
Get the big buckmug. by Kittie September 10, 2003
 Get the buck wildmug.
Get the buck wildmug. That moron who crashed the stolen Tiburon into the tree on my street was probably doing a buck fifty in a 40 zone.
by Svedenhaus July 31, 2007
 Get the a Buck Fiftymug.
Get the a Buck Fiftymug.