Thin, as a voice (5)
I believe the answer is:
reedy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thin as a voice</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for reedy that I've seen before include "Grassed up" , "Thin and piping" , "abounding with grasses" , "edge of some river-banks" , "Sounding thin - weak" .)