Tennis's Steffi
I believe the answer is:
graf
'tennis's steffi' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for graf that I've seen before include "Steffi --, tennis player" , "German tennis player, b. 1969" , "Seven-times women's Wimbledon champion, b. 1969" , "Noted tennis player" , "Steffi --, tennis champion" .)