succubus vs fiend

succubus and fiend both are nouns.

Word	Noun	Adjective	Verb	Adverb
succubus	Yes	No	No	No
fiend	Yes	No	No	No

As nouns, fiend is a hypernym of succubus; that is, fiend is a word with a broader meaning than succubus:

succubus: a female demon believed to have sexual intercourse with sleeping men
fiend: an evil supernatural being

Other hypernyms of succubus include daemon, daimon, demon, devil.

succubus (noun)	fiend (noun)
a female demon believed to have sexual intercourse with sleeping men	a cruel wicked and inhuman person
	a person motivated by irrational enthusiasm (as for a cause)
	an evil supernatural being