Seri is a language isolate spoken by about a thousand people in two villages on the coast of Sonora, Mexico. The native name for the language, cmiique iitom, means '(that) with which a Seri person speaks'. The language has also been called kunkaak, a version of the native name for the Seri people, comcaac. The origins of the name Seri are uncertain but are thought to come from another language in the region.
Seri is thought to be the last surviving member of its language family and nothing is know of the other members. Efforts to find links between Seri and other languages, such as the Hokan, Pomoan and Chontal languages, have produced no clear evidence of connections.
source
wikipedia.org,
omniglot.com &
ethnologue.com