Navaho language vs Athapascan

Navaho language and Athapascan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Navaho language	Yes	No	No	No
Athapascan	Yes	No	No	No

As nouns, Athapascan is a hypernym of Navaho language; that is, Athapascan is a word with a broader meaning than Navaho language:

Navaho language: the Athapaskan language spoken by the Navaho
Athapascan: a group of Amerindian languages (the name coined by an American anthropologist, Edward Sapir)

Other hypernyms of Navaho language include Athabascan, Athabaskan, Athapaskan, Athapaskan language.

Navaho language (noun)	Athapascan (noun)
the Athapaskan language spoken by the Navaho	a group of Amerindian languages (the name coined by an American anthropologist, Edward Sapir)
	a member of any of the North American Indian groups speaking an Athapaskan language and living in the subarctic regions of western Canada and central Alaska