Finished when cheated (4)
I believe the answer is:
done
I believe this is a double definition.
'finished' is the first definition.
(both can mean completed)
'cheated' is the second definition.
'when' is the link.
(Other definitions for done that I've seen before include "Thoroughly cooked; accomplished" , "(Of food) well cooked" , "Concluded (and dusted?)" , "Robbed" , "Artist's workroom" .)