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