Kwannon vs Guanyin

Kwannon and Guanyin both are nouns.

Word	Noun	Adjective	Verb	Adverb
Kwannon	Yes	No	No	No
Guanyin	Yes	No	No	No

As nouns, Kwannon and Guanyin are synonyms defined as:

Kwannon (noun)	Guanyin (noun)
Japanese counterpart of Chinese Kuan Yin	Japanese counterpart of Chinese Kuan Yin
	(Buddhism) a female Bodhisattva; often called the Goddess of Mercy and considered an aspect of the Bodhisattva Avalokiteśvara; identified with Japanese Kwannon