/ Dictionary / Index F f-stop: Meaning and Definition of Find definitions for: f-stop Pronunciation: (ef'stop"), [key] — n. Photog. the setting of an adjustable lens aperture, as indicated by an f number. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. F star Ft. Related Content Daily Word Quiz: malady Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language