/ Dictionary / Index F forty-fifth: Meaning and Definition of Find definitions for: for•ty-fifth Pronunciation: (fôr'tē fifth' or, often, -fith'), [key] — adj. next after the forty-fourth; being the ordinal number for 45. being one of 45 equal parts. —n. a forty-fifth part, esp. of one (). the forty-fifth member of a series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: forty-fifth (Thesaurus) forty-eightmo forty-first Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language