Quechua vs Kechuan

Quechua and Kechuan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Quechua	Yes	No	No	No
Kechuan	Yes	Yes	No	No

As nouns, Quechua and Kechuan are synonyms defined as:

Quechua and Kechuan: the language of the Quechua which was spoken by the Incas

Quechua (noun)	Kechuan (noun)
the language of the Quechua which was spoken by the Incas	the language of the Quechua which was spoken by the Incas
a community of South American Indians in Peru who were formerly the ruling class of the Incan Empire
a member of a South American Indian people in Peru who were formerly the ruling class of the Inca empire

Quechua (adjective)	Kechuan (adjective)
	of or relating to the Quechua or their language