subvocalize vs say

subvocalize is not a noun while say is a noun.

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

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

Other hypernyms of subvocalize include articulate, enounce, enunciate, pronounce, sound out.

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

subvocalize (verb)	say (verb)
articulate without making audible sounds	express in words
	report or maintain
	speak, pronounce, or utter in a certain way
	express a supposition
	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