Wild mountain goat (4)

I believe the answer is:
ibex
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wild mountain goat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ibex that I've seen before include "Mountain goat with long curved horns" , "being nimble-footed" , "Mountain-goat" , "Wild goat of North Africa" , "Large-horned mountain goat" .)