Ferocious fish (7)
I believe the answer is:
piranha
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ferocious fish</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 piranha that I've seen before include "fish chewed up" , "Voracious eater" , "Ferocious fish" , "This predator" , "Sharp-toothed fish" .)