dope slap 

A light "whappp" to the back of the head, done with an open palm in an upward motion. The physical equivalent of the phrase, "Whatta you, a moron?!"

Someone oughta give that damn Illinois driver a dope slap for driving like an idiot!

dope slap by JonathanChance June 28, 2003

dopeslap

Tagging anyone in the back of the neck unexpectedly for doing something particularly stupid.

Commonly done by mothers.

Mom quickly dopeslapped billy for oogling Mrs. Kent's daughter thru the window.

dopeslap by UA August 26, 2004

dopeslap

a dopeslap is what happens when two clueless people try elaborate handshakes at the same time.

It is funny watching jesse and chris dopeslap each other.

dopeslap by churchyard October 14, 2014