Orca (6,5)
I believe the answer is:
killer whale
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">orca</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for killer whale that I've seen before include "Marine mammal" , "Orca" , "Marine predator" , "Predatory relative of dolphin" .)