Athapaskan language vs Athabascan

Athapaskan language and Athabascan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Athapaskan language	Yes	No	No	No
Athabascan	Yes	No	No	No

As nouns, Athapaskan language and Athabascan are synonyms defined as:

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

Other synonyms of Athapaskan language include Athabaskan, Athapascan, Athapaskan.

Athapaskan language (noun)	Athabascan (noun)
a group of Amerindian languages (the name coined by an American anthropologist, Edward Sapir)	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