Biological bristle (4)
I believe the answer is:
seta
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">biological bristle</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for seta that I've seen before include "bristle-like appendage" , "Criminals make the best detectives" , "bristle" .)