say vs announce

say is a noun but announce is not a noun.

Word	Noun	Adjective	Verb	Adverb
say	Yes	No	Yes	No
announce	No	No	Yes	No

As verbs, announce is a hyponym of say; that is, announce is a word with a more specific, narrower meaning than say:

say (noun)	announce (noun)
the chance to speak

say (verb)	announce (verb)
express in words	make known; make an announcement
report or maintain	foreshadow or presage
speak, pronounce, or utter in a certain way	announce publicly or officially
express a supposition	give the names of
give instructions to or direct somebody to do something with authority
communicate or express nonverbally
recite or repeat a fixed text
indicate
state as one's opinion or judgement; declare
utter aloud
have or contain a certain wording or form