Swimsuit (6)
I believe the answer is:
bikini
'swimsuit' is the definition.
(bikini is a kind of swimsuit)
This is the entire clue.
(Other definitions for bikini that I've seen before include "Two piece swimsuit" , "Brief two-piece swimming costume" , "tests were carried out here" , "bomb site" , "Small bathing costume or atoll in Marshall Islands" .)