Smack On means to propose a fight with someone. Generally in a joking manner but can definitely can be used very effectively in a real situation. Smack On is closely associated with the term "punch on".
Joking:
Luke: "You suck apples"
Brad: "Smack on cunt"
Serious:
Josh: "I fucked your ex on a trampoline!"
Ryan: "Smack on cunt!"
Luke: "You suck apples"
Brad: "Smack on cunt"
Serious:
Josh: "I fucked your ex on a trampoline!"
Ryan: "Smack on cunt!"
by KinnyMcbinspin February 04, 2014
by liv March 21, 2005
by Bigg Phill January 27, 2010
by Sickyle January 29, 2003
First invented (allegedly) by Dan Mace. Means let's get things done. A whole episode of 368 by Casey Neistat is titled after this phrase "SMACK IT."
by Amycrackpot April 20, 2018
by Smack That June 11, 2014