/ Dictionary / Index F fastback: Meaning and Definition of Find definitions for: fast•back Pronunciation: (fast'bak", fäst'-), [key] — n. a form of back for an automobile body consisting of a single, unbroken convex curve from the top to the rear bumper. a car having such a back. Cf. notchback. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. fast fastball Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language