prophesy vs prognosticate

prophesy and prognosticate both are verbs.

Word	Noun	Adjective	Verb	Adverb
prophesy	No	No	Yes	No
prognosticate	No	No	Yes	No

As verbs, prognosticate is a hypernym of prophesy; that is, prognosticate is a word with a broader meaning than prophesy:

Other hypernyms of prophesy include anticipate, call, forebode, foretell, predict, promise.

prophesy (verb)	prognosticate (verb)
predict or reveal through, or as if through, divine inspiration	make a prediction about; tell in advance
deliver a sermon	indicate, as with a sign or an omen