A "Sigbjorn" is a devastating attack to the testicles.

Derived from a viking named Sigbjorn who punched testicles like no other. In norwegian, the name Sigbjorn means "Sick Bear", which might explain the fascination for inflicting perverse harm on unsuspecting people. Be wary, men who are given this name are likely to grow up to become nut-punchers of legend.
Jackson : Dude, what's with all the blood?

Steve : Some guy sigbjorned me..
by NorseScholar November 1, 2009
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