Fair sets sometimes played with clenched hand (4)
I believe the answer is:
fist
'clenched hand' is the definition.
(I've seen this before)
'fair sets sometimes' is the wordplay.
'sometimes' means one should take alternating letters (some of the letters are taken at regular intervals).
'fair'+'sets'='fairsets'
The alternating letters of 'fairsets' are 'FIST'.
'played with' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for fist that I've seen before include "Hand with the fingers clenched in the palm" , "Balled hand" , "handwriting?" , "duke" , "Hit with a clenched one" .)