Tennis star Arthur (4)
I believe the answer is:
ashe
'tennis star 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, who came to court" , "Arthur, first black Wimbledon men's singles champion, 1975" , "US tennis player Arthur, 1975 Wimbledon champion" , "US court star" , "Ex-Wimbledon champ" .)