1. n. A challenge match, used to test the fighting skills of an individual, school, lineage or style (sometimes all four).
2. v. To challenge someone to gong sau.
3. An exclamation indicating a strong desire for definition 1.
-From the Cantonese Chinese language.
-Similar to a Gracie Challenge except this was fought on the streets. In Hong Kong these would be often fought on the roofs of buildings since there was not enough room on the streets.