Arctic deer (7)
I believe the answer is:
caribou
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">arctic deer</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 caribou that I've seen before include "Arctic beast" , "North American Arctic deer" , "US reindeer" , "Wild animal" , "Creature" .)