Character I'm thinking about keen to reveal cheat (11)

'cheat' is the definition.
(cardsharper is a kind of cheat)

'character i'm thinking about keen' is the wordplay.
I cannot quite understand how this works, but
'character' could be 'sharp' (I have seen 'Unscrupulous character' mean 'sharp' so perhaps 'character' could also mean 'sharp') and 'sharp' is located in the answer.
'about' could be 'ca' (abbreviation for 'circa') and 'ca' is found within the answer.
'i'm thinking' could be 'er' (expression used when hesitating) and 'er' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

'to reveal' is the link.

Can you help me to learn more?