An extinct Caucasian language spoken exclusively in Turkey WordNet 3.0 & Open English WordNet

Ubykh or Päkhy is an extinct Northwest Caucasian language once spoken by the Ubykh people, a subgroup of Circassians who originally inhabited the eastern coast of the Black Sea before being deported en masse to the Ottoman Empire in the Circassian genocide. Wikipedia

Extinct Northwest Caucasian language once spoken by the Ubykh people Wikidata

A language of the Northwestern Caucasian group, spoken by the Ubykh people up until the early 1990s. OmegaWiki

The extinct ergative and agglutinative language spoken by the Ubykh people, notable for its large number of distinct consonants and only two vowels. Wiktionary