Legendary Arthur (4)
I believe the answer is:
ashe
'legendary arthur' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ashe that I've seen before include "Arthur, first black Wimbledon men's singles champion, 1975" , "He was good enough to win Wimbledon" , "Arthur, who came to court" , "Ex-Wimbledon champ" , "tennis champ" .)