/ Dictionary / Index C cosmonaut: Meaning and Definition of Find definitions for: cos•mo•naut Pronunciation: (koz'mu-nôt", -not"), [key] — n. a Russian or Soviet astronaut. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cosmonaut (Thesaurus) cosmology cosmonautics Related Content Daily Word Quiz: reclusive Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language