Large edible crustacean (7)
I believe the answer is:
lobster
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">large edible crustacean</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lobster that I've seen before include "potted" , "Bolster up te shellfish" , "Eight-legged shellfish, scarlet when boiled" , "Tommy no longer" , "One showing claws" .)