Guanyin vs Kwannon

Guanyin and Kwannon both are nouns.

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

As nouns, Guanyin and Kwannon are synonyms defined as:

Guanyin (noun)	Kwannon (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