fetish vs sexual desire

fetish and sexual desire both are nouns.

Word	Noun	Adjective	Verb	Adverb
fetish	Yes	No	No	No
sexual desire	Yes	No	No	No

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

fetish: 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
sexual desire: a desire for sexual intimacy

Other hypernyms of fetish include concupiscence, eros, physical attraction.

fetish (noun)	sexual desire (noun)
excessive or irrational devotion to some activity	a desire for sexual intimacy
a charm superstitiously believed to embody magical powers
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