/ Dictionary / Index O ornithorhynchus: Meaning and Definition of Find definitions for: or•ni•tho•rhyn•chus Pronunciation: (ôr"nu-thu-ring'kus), [key] — n. the platypus. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ornithorhynchus (Thesaurus) ornithopter ornithosis Related Content Daily Word Quiz: apogee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language