fetish vs devotion

fetish and devotion both are nouns.

Word	Noun	Adjective	Verb	Adverb
fetish	Yes	No	No	No
devotion	Yes	No	No	No

As nouns, devotion is a hypernym of fetish; that is, devotion is a word with a broader meaning than fetish:

fetish (noun)	devotion (noun)
excessive or irrational devotion to some activity	(usually plural) religious observance or prayers (usually spoken silently)
a charm superstitiously believed to embody magical powers	commitment to some purpose
a form of sexual desire in which gratification depends to an abnormal degree on some object or item of clothing or part of the body	religious zeal; the willingness to serve God
	feelings of ardent love