arithmancy vs fortune telling

arithmancy and fortune telling both are nouns.

Word	Noun	Adjective	Verb	Adverb
arithmancy	Yes	No	No	No
fortune telling	Yes	No	No	No

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

arithmancy: divination by means of numbers
fortune telling: the art or gift of prophecy (or the pretense of prophecy) by supernatural means

Other hypernyms of arithmancy include divination, foretelling, soothsaying.

arithmancy (noun)	fortune telling (noun)
divination by means of numbers	the art or gift of prophecy (or the pretense of prophecy) by supernatural means