Webster's Revised Unabridged Dictionary · 1913

Miohippus

Miohippus (mī`o*hip"pus) , noun

[New Latin, from Greek mei`wn less + "ippo`s horse.]

(Paleontology) An extinct Miocene mammal of the Horse family, closely related to the genus Anhithecrium, and having three usable hoofs on each foot.