Cruel process shows a profit (5)
I believe the answer is:
lucre
'a profit' is the definition.
(I know that profit can be written as lucre)
'cruel process' is the wordplay.
'process' indicates anagramming the letters.
'cruel' anagrammed gives 'LUCRE'.
'shows' is the link.
(Other definitions for lucre that I've seen before include "Cruel kind of money, may be filthy" , "(Filthy) profit" , "There's money" , "Scornful word for money that may be 1 Across" , "ill-gotten gains" .)