Monkey scratching bottom sees rook (4)
I believe the answer is:
scam
'rook' is the definition.
(I know that rook can be written as scam)
'monkey scratching bottom' is the wordplay.
'monkey' becomes 'scamp' (both can mean a mischievous child).
'scratching bottom' means to remove the last letter.
'scamp' with its final letter taken away is 'SCAM'.
'sees' is the link.
(Other definitions for scam that I've seen before include "Dubious operation" , "Confidence trick, swindle" , "ploy" , "Swindle (sl.)" , "Dodgy business" .)