gong sau
1. n.  A challenge match, used to test the fighting skills of an individual, school, or style (sometimes all three).

2. v.  To challenge someone to gong sau.

3. An exclamation indicating a strong desire for definition 1.
1. "Hey man, gong sau tomorrow, bring your wraps and mouthpiece."

2. "I tried to gong sau Phil Elmore, but he backed down like the punk he is."

3. "GONG SAU!!!!!!!!!!!!!!"