About the tom cats, 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)
'about the tom cats' is the wordplay.
'about' means one lot of letters goes inside another.
'the tom' becomes 'he' (I am not sure about this - if you are sure you should believe this answer much more).
'he' put within 'cats' is 'CHEATS'.
Can you help me to learn more?
(Other definitions for cheats that I've seen before include "Acts dishonestly in chaste way" , "Chaste kind of swindlers" , "Chaste (anag.)" , "Acts dishonestly, perhaps in card game" , "Swindles in chaste manner" .)