Large tuna (8)
I believe the answer is:
albacore
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">large tuna</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 albacore that I've seen before include "Variety of tuna" , "Long-fin tunny" , "fish" , "Large tuna; able orca (anag.)" .)