Doesn't play fair (6)
I believe the answer is:
cheats
'doesn't play fair' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cheats that I've seen before include "Deceives as in card game" , "Dishonest dealers" , "Deceivers" , "Swindles, defrauds" , "Chaste (anag.)" .)