Invertebrate (9)
I believe the answer is:
earthworm
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">invertebrate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(earthworm is a kind of invertebrate)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for earthworm that I've seen before include "What mole eats" , "Burrowing creature" , "Soil-dwelling invertebrate" , "One burrows" , "Creature that burrows in soil" .)