Charlie smuggled by decoy for ill-gotten gains (5)
I believe the answer is:
lucre
'ill-gotten gains' is the definition.
(I've seen this before)
'charlie smuggled by decoy' is the wordplay.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'smuggled by' indicates putting letters inside (I've seen this in other clues).
'decoy' becomes 'lure' (synonyms).
'c' inserted inside 'lure' is 'LUCRE'.
'for' acts as a link.
(Other definitions for lucre that I've seen before include "Ill-gotten riches" , "Money or wealth" , "benefits from crime" , "There's money" , "Profit dishonestly obtained" .)