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1.
1. The action of one male slapping another male on the backside in a celebratory act.
1. Did you see that! Vettori got a wicket, now the team are Black Capping each other.
by Kip Stevens April 22, 2004
 
2.
The act of congratulating another person by patting them on the butt. Typically blackcapping is only appropriate in competitive sports games but even then intentions can remain dubious.

Originating from the TV sport comedy series Pulp Sport and named after the New Zealand cricket team, the Blackcaps.
"He went around blackcapping all the guys after we won.... he wasn't even part of the team!"
by epinema January 04, 2012