Swimming costume (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">swimming costume</span>' is the definition.<br/ ><span class="explanation-format__explanation">(bikini is a kind of swimming costume)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for bikini that I've seen before include "Skimpy garment" , "strip of beach" , "Infamous atoll" , "practised here with explosive results" , "Women's tiny bathing costume" .)