Tennis' Arthur (4)
I believe the answer is:
ashe
'tennis' arthur' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ashe that I've seen before include "Sporting champion once" , "US tennis player Arthur, 1975 Wimbledon champion" , "US rallying champion" , "Ex-Wimbledon champ" , "Arthur, first black Wimbledon men's singles champion, 1975" .)