Bathing suit (6)
I believe the answer is:
bikini
'bathing suit' is the definition.
(bikini is a kind of bathing suit)
This is the entire clue.
(Other definitions for bikini that I've seen before include "Kind of swimsuit" , "Pacific atoll, used for US nuclear weapons tests" , "Skimpy bathing costume or Pacific atoll" , "Bathing suit for the atoll?" , "Skimpy two-piece swim wear" .)