/ Dictionary / Index S Sinn Fein: Meaning and Definition of Find definitions for: Sinn Fein Pronunciation: (shin' fān'), [key] a political organization in Ireland, founded about 1905, advocating the complete political separation from Great Britain of a unified Ireland. a member of this organization. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sinnet sinningia Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language