say vs articulate

say is a noun but articulate is not a noun.

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

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

As verbs, say and articulate are synonyms defined as:

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

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

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

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