/ Dictionary / Index R Rosario: Meaning and Definition of Find definitions for: Ro•sa•ri•o Pronunciation: (rō-zär'ē-ō", -sär'- Sp. rô-sä'ryô), [key] — n. a port in E Argentina, on the Paraná River. 954,606. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rosario (Thesaurus) rosarian rosarium Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language