Definition of Orohippus in US English:

Orohippus

noun

  • A genus of extinct small equids having four toes on the forefeet and three on the hind feet, known from fossils found in Middle to Upper Eocene deposits in North America; a horse of this genus.

Origin

Late 19th century; earliest use found in John William Dawson (1820–1899), geologist and educationist. From scientific Latin Orohippus, genus name from oro- oro- + -hippus (in protohippus).