Algonquian vs Algonkin

Algonquian and Algonkin both are nouns.

Word	Noun	Adjective	Verb	Adverb
Algonquian	Yes	Yes	No	No
Algonkin	Yes	No	No	No

As nouns, Algonkin is a hyponym of Algonquian; that is, Algonkin is a word with a more specific, narrower meaning than Algonquian:

Algonquian: family of North American Indian languages spoken from Labrador to South Carolina and west to the Great Plains
Algonkin: the Algonquian language spoken by the Algonkian

As nouns, Algonkin is a hyponym of Algonquian; that is, Algonkin is a word with a more specific, narrower meaning than Algonquian:

Algonquian: a member of any of the North American Indian groups speaking an Algonquian language and originally living in the subarctic regions of eastern Canada; many Algonquian tribes migrated south into the woodlands from the Mississippi River to the Atlantic coast
Algonkin: a member of a North American Indian people in the Ottawa river valley of Ontario and Quebec

Algonquian (noun)	Algonkin (noun)
family of North American Indian languages spoken from Labrador to South Carolina and west to the Great Plains	the Algonquian language spoken by the Algonkian
a member of any of the North American Indian groups speaking an Algonquian language and originally living in the subarctic regions of eastern Canada; many Algonquian tribes migrated south into the woodlands from the Mississippi River to the Atlantic coast	a member of a North American Indian people in the Ottawa river valley of Ontario and Quebec

Algonquian (adjective)	Algonkin (adjective)
of or relating to an Algonquian tribe or its people or language