/ Dictionary / Index O oratorio: Meaning and Definition of Find definitions for: or•a•to•ri•o Pronunciation: (ôr"u-tôr'ē-ō", -tōr'-, or"-), [key] — pl. -ri•os. an extended musical composition with a text more or less dramatic in character and usually based upon a religious theme, for solo voices, chorus, and orchestra, and performed without action, costume, or scenery. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: oratorio (Thesaurus) oratorical oratory Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language