Karate expert (3)
I believe the answer is:
dan
'karate expert' is the definition.
(person who has been awarded a dan in karate)
This is all the clue.
(Other definitions for dan that I've seen before include "-- Dare, comic hero" , "The 19's first archer" , "book (abbreviated version)" , "Expertise level in juso" , "Dark and damp." .)