Make money if port is drunk (6)
I believe the answer is:
profit
'make money' is the definition.
'if port is drunk' is the wordplay.
'is drunk' is an anagram indicator.
'if'+'port'='ifport'
'ifport' is an anagram of 'PROFIT'.
(Other definitions for profit that I've seen before include "Financial gain" , "Net gain after expenses" , "Money made" , "Yield - gain" , "returns" .)