Japanese vs Altaic language

Japanese and Altaic language both are nouns.

Word	Noun	Adjective	Verb	Adverb
Japanese	Yes	Yes	No	No
Altaic language	Yes	No	No	No

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

Japanese: the language (usually considered to be Altaic) spoken by the Japanese
Altaic language: a group of related languages spoken in Asia and southeastern Europe

Other hypernyms of Japanese include Altaic.

Japanese (noun)	Altaic language (noun)
the language (usually considered to be Altaic) spoken by the Japanese	a group of related languages spoken in Asia and southeastern Europe
a native or inhabitant of Japan

Japanese (adjective)	Altaic language (adjective)
of or relating to or characteristic of Japan or its people or their culture or language