Pill bug or wood louse (6)
I believe the answer is:
isopod
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pill bug or wood louse</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 isopod that I've seen before include "Woodlouse, say" , "This crusty creature" , "Slater, for instance" , "Crawler" , "Member of an order of crustaceans" .)