Slender woman (5)
I believe the answer is:
sylph
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">slender woman</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 sylph that I've seen before include "Slim person" , "Imaginary spirit of the air" , "Slender, graceful girl" , "Graceful lass" , "slender lass!" .)