/ Dictionary / Index H hesperornis: Meaning and Definition of Find definitions for: hes•per•or•nis Pronunciation: (hes"pu-rôr'nis), [key] — n. a toothed aquatic bird of the extinct genus Hesperornis, fossils of which are found in rocks of Cretaceous age in Kansas, having the rear legs modified for swimming and reaching a length of more than 4 ft. (1.2 m). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hesperinos Hesperus Related Content Daily Word Quiz: respite Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language