sibyl vs fortune teller

sibyl and fortune teller both are nouns.

Word	Noun	Adjective	Verb	Adverb
sibyl	Yes	No	No	No
fortune teller	Yes	No	No	No

As nouns, fortune teller is a hypernym of sibyl; that is, fortune teller is a word with a broader meaning than sibyl:

Other hypernyms of sibyl include fortuneteller.

sibyl (noun)	fortune teller (noun)
(ancient Rome) a woman who was regarded as an oracle or prophet	a person who foretells your personal future
a woman who tells fortunes