Savagely fierce (9)
I believe the answer is:
ferocious
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">savagely fierce</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 ferocious that I've seen before include "potentially harmful" , "Savagely cruel" , "Savage as a wild beast" , "very intense" , "Savagely fierce" .)