xenoglossy means knowledge of a language one has never learned. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
xenoglossy is pronounced /ˌziːnəˈɡlɒsi/.
Why “xenoglossy” is a great word
The purported ability to speak or understand a language one has never learned. From xeno- (from Greek xenos, "foreign") + -glossia (from Greek glōssa, "tongue, language"), borrowed from French xénoglossie. First attested in English in 1914 in a translation by A. T. de Mattos. Unlike glossolalia, which produces ecstatic, invented syllables, or the hard-won fluency of a polyglot, xenoglossy claims an impossible, instant mastery of a verifiable tongue. It is the sudden, flawless Urdu issuing from a Vermont farmhand in a trance; the forgotten Cypriot dialect spoken in the fever of a high dream; the perfect, untaught Latin prayer rising from a child's lips—a haunting proposition that memory might leak across the boundaries of a single life.
Etymology
From xeno- + -glossia, borrowed from French xénoglossie.
noun
- Knowledge of a language one has never learned.“The most well-documented case of xenoglossy, however, concerned Swiss Medium Hélène Smith (1861-1929), who falsely claimed to speak the Martian language.”
- Glossolalia.