/ Dictionary / Index F F.O.S.: Meaning and Definition of Find definitions for: F.O.S. Pronunciation: [key] free on station. free on steamer. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: fos (Thesaurus) forzando Fosdick Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language