/ Dictionary / Index F firth: Meaning and Definition of Find definitions for: firth Pronunciation: (fûrth), [key] — n. Chiefly Scot. a long, narrow indentation of the seacoast. Firth Pronunciation: (fûrth), [key] — n. 1890–1960, English linguist. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: firth (Thesaurus) First World War fisc Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language