articulate vs say

articulate is not a noun while say is a noun.

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

As verbs, articulate and say are synonyms defined as:

Other synonyms of articulate include enounce, enunciate, pronounce, sound out.

As verbs, say is a hypernym of articulate; that is, say is a word with a broader meaning than articulate:

Other hypernyms of articulate include state, tell.

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

articulate (adjective)	say (adjective)
expressing yourself easily or characterized by clear expressive language
consisting of segments held together by joints

articulate (verb)	say (verb)
speak, pronounce, or utter in a certain way	express in words
express or state clearly	report or maintain
put into words or an expression	speak, pronounce, or utter in a certain way
provide with a joint	express a supposition
unite by forming a joint or joints	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