Webster's Revised Unabridged Dictionary · 1913

Hesperornis

Hesperornis , noun

[New Latin, from Greek {not transcribed} western + {not transcribed}, {not transcribed}, a bird.]

(Paleontology) A genus of large, extinct, wingless birds from the Cretaceous deposits of Kansas, belonging to the Odontornithes. They had teeth, and were essentially carnivorous swimming ostriches. Several species are known. See Illust. in Append.