Sinn fein sin-mortifying • Sinn feiner · · · Info · Definitions · Characters · · Sinn fein · · Text Common · · Latin · · Scripts 9 · · Length Definitions · · · (noun) an Irish republican political movement founded in 1905 to promote independence from England and unification of Ireland; became the political branch of the Irish Republican Army. Synonyms: Sinn Fein. · · Noun Definition 1 Characters · · space U+0020 S latin capital letter s U+0053 e latin small letter e U+0065 f latin small letter f U+0066 i latin small letter i U+0069 n latin small letter n U+006E