Hints may be very loud in card game finishing early (6)
I believe the answer is:
whiffs
'hints' is the definition.
(both can mean a trace)
'very loud in card game finishing early' is the wordplay.
'very loud' becomes 'ff' (musical abbreviation).
'in' is an insertion indicator.
'card game' becomes 'whist' (whist is a kind of card game).
'finishing early' means to remove the last letter.
'whist' with its last letter taken away is 'whis'.
'ff' inserted into 'whis' is 'WHIFFS'.
'may be' is the link.
(Another definition for whiffs that I've seen is " Unpleasant smells".)