Spirit has a profit (4)
I believe the answer is:
gain
'profit' is the definition.
(I know that profit can be written as gain)
'spirit has a' is the wordplay.
'spirit' becomes 'gin' (alcoholic spirit).
'has' indicates putting letters inside.
'gin' enclosing 'a' is 'GAIN'.
(Other definitions for gain that I've seen before include "Earn, profit" , "Profit; acquire" , "Obtain to one's advantage" , "reward" , "Win" .)