annunciate vs herald

annunciate is not a noun while herald is a noun.

Word	Noun	Adjective	Verb	Adverb
annunciate	No	No	Yes	No
herald	Yes	No	Yes	No

As verbs, annunciate and herald are synonyms defined as:

Other synonyms of annunciate include announce, foretell, harbinger.

annunciate (noun)	herald (noun)
	something that precedes and indicates the approach of something or someone
	(formal) a person who announces important news

annunciate (verb)	herald (verb)
foreshadow or presage	foreshadow or presage
	praise vociferously
	greet enthusiastically or joyfully