Insect in its adult form (5)
I believe the answer is:
imago
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">insect in its adult form</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 imago that I've seen before include "Sexually mature adult insect" , "Last stage of adult insect" , "Maybe comma" , "Comma perhaps" , "Fully-developed insect" .)