Wild ass (6)
I believe the answer is:
onager
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wild ass</span>' is the definition.<br/ ><span class="explanation-format__explanation">(onager is a kind of wild ass)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for onager that I've seen before include "wild beast" , "The ass is a strange orange" , "donkey" , "Asian wild ass - orange (anag)" , "Variety of wild ass found in central Asia" .)