Are inclined to enter knockout competition to make a lot of money (5,2)
I believe the answer is:
clean up
'make a lot of money' is the definition.
(I've seen this before)
'are inclined to enter knockout competition' is the wordplay.
'are inclined to' becomes 'lean' (I can't explain this - if you can you should give a lot more credence to this answer).
'enter' indicates putting letters inside.
'knockout competition' becomes 'cup'.
'lean' put within 'cup' is 'CLEAN-UP'.
'to' is the link.
Can you help me to learn more?
(Other definitions for clean up that I've seen before include "Make a substantial profit" , "Make a great profit" , "Win everything!" , "Make a lot of money" , "Thorough decontamination" .)