Large edible flatfish (7)
I believe the answer is:
halibut
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">large edible flatfish</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 halibut that I've seen before include "Marine food fish" , "One's scaled" , "Large flatfish, tasty to eat" , "Utah lib (anag)" , "Something fishy here" .)