/ Dictionary / Index F fornix: Meaning and Definition of Find definitions for: for•nix Pronunciation: (fôr'niks), [key] — pl. -ni•ces any of various arched or vaulted structures, as an arching fibrous formation in the brain. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: fornix (Thesaurus) forniciform for-profit Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language