Topless bather's new suit (6)
I believe the answer is:
Here is my best explanation:
'suit' is the definition.
(I've seen this before)
'topless bather's new' is the wordplay.
'topless' means to remove the first letter.
'new' indicates anagramming the letters.
'bathers' with its first letter taken off is 'athers'.
'athers' anagrammed gives 'HEARTS'.