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1.
A smack back is whatever you want it to be. Usually relating to someone or something that is wack, lame, weak, or ugly. Can also be used as a greeting term. Like what up nigga, dog, playa, killah, ninja, ect. Smackback is a word such as bad. Can be used for good or evil. So basically its anything u want it to be.
What up Smackback? Look at this mutha***** smackback lol
by Kyser Soze November 07, 2007
 
2.
a term used in volleyball, when a person slams the ball over the net at an opposite team member. it could only be forfilled when the other person does not return the ball.
sally hits the ball up to kelly,
kelly hits the ball over the net
and cally was unable to return it
brandon to phil "what a smack-back!!!"
by sternburger November 20, 2006