/ Dictionary / Index F Fidelio*: Meaning and Definition of Find definitions for: Fi•de•lio Pronunciation: (fi-dāl'yō), [key] — n. an opera (1805) by Ludwig van Beethoven. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Fidel Fidelism Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language