Ballet dancer's skirt (4)
I believe the answer is:
tutu
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ballet dancer's skirt</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tutu that I've seen before include "Ballet dancer's costume" , "Ballet dress" , "Giselle's skirt" , "The old primate" , "Female ballet costume" .)