Glossolalia

Glossolalia or speaking in tongues is the fluid vocalizing (or less commonly, the writing) of speech-like syllables which lack any readily comprehended meaning, in some cases as part of religious practice. The significance of glossolalia has varied in context, with some minorities considering it as a part of a sacred language. It is most prominently practiced within Pentecostal and Charismatic Christianity, but it is also practiced in non-Christian religions.

Glossolalia also sometimes refers to xenoglossy, which is speaking in a natural language that was previously unknown to the speaker.