Cheat swapping spades for diamonds in contract (7)
I believe the answer is:
swindle
'cheat' is the definition.
(swindling is a kind of cheating)
'swapping spades for diamonds in contract' is the wordplay.
I cannot really see how this works, but
'spades' could be 's' (abbreviation in card games) and 's' is located in the answer.
'diamonds' could be 'd' (abbreviation for the card suit diamonds) and 'd' is located in the answer.
'in' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for swindle that I've seen before include "Fraudulent action" , "Cheat; fraud" , "Diddle, sting, twist" , "Con, defraud" , "Rip off" .)