An endangered language or moribund language is a language that is at risk of disappearing as its speakers die out or shift to speaking other languages. Language loss occurs when the language has no more native speakers and becomes a "dead language". If no one can speak the language at all, it becomes an "extinct language". A dead language may still be studied through recordings or writings, but it is still dead or extinct unless there are fluent speakers. Although languages have always become extinct throughout human history, they are currently dying at an accelerated rate because of globalization, mass migration, cultural replacement, imperialism, neocolonialism and linguicide.

The Ryukyuan languages , also Lewchewan or Luchuan, are the indigenous languages of the Ryukyu Islands, the southernmost part of the Japanese archipelago. Along with the Japanese language and the Hachijō language, they make up the Japonic language family.