Ranked, in tennis (6)
I believe the answer is:
seeded
'ranked in tennis' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for seeded that I've seen before include "Sown" , "Planted like top tennis player" , "Graded in first 16 players of tennis tournament" , "In tennis tournament, graded in first sixteen" , "Ranked in first 16 of tennis tournament" .)