Glossolalia

Glossolalia or speaking in tongues is the fluid vocalizing (or, less commonly, the writing) of speech-like syllables, often as part of religious practice.[1] The significance of glossolalia has varied with time and place, with some considering it a part of a sacred language. It is most prominently practiced within Pentecostal and Charismatic Christianity, but it is practiced in non-Christian religions as well. Others believe that the vocalizations are meaningless and cite hypnosis, mental illness, and social learning as scientific explanations.
Glossolalia also sometimes refers to xenoglossy, which is speaking in a natural language that was previously unknown to the speaker.