Highest adult female voice (7)
I believe the answer is:
soprano
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">highest adult female voice</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 soprano that I've seen before include "Woman singing" , "(Singer of) the highest vocal range" , "Female singing voice" , "Highly vocal musician" , "chorus girl, perhaps" .)