Mythical horse-man (7)
I believe the answer is:
centaur
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mythical horse-man</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 centaur that I've seen before include "Mythical equine creature" , "Horsey person" , "Mythic man-horse" , "Half-man and half horse" , "Mythical semi-equine beast" .)