Low neckline (11)
I believe the answer is:
decolletage
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">low neckline</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for decolletage that I've seen before include "Low neckline" , "Revealing cut" , "Dress style" , "Low-cut neckline" .)