look up any word, like lemonparty:
 
1.
To have sex from the back, hit it from behind, doggystyle. Doing this hard and fast so that it makes a smacking noise.
That girls hot, I want to smack that.
by jennw January 12, 2007
 
2.
Giving a booty a little tap or a squeeze on the ass cheeks. Typically a saying or a phrase.
Shawty didn't like it when I came up behind her and decided smack that good looking booty of hers.
by Smack That June 10, 2014