fortune teller vs soothsayer

fortune teller and soothsayer both are nouns.

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

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

fortune teller: a person who foretells your personal future
soothsayer: someone who makes predictions of the future (usually on the basis of special knowledge)

Other hypernyms of fortune teller include forecaster, predictor, prognosticator.

fortune teller (noun)	soothsayer (noun)
a person who foretells your personal future	someone who makes predictions of the future (usually on the basis of special knowledge)