opportunity vs say

opportunity and say both are nouns.

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

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

opportunity (noun)	say (noun)
a possibility due to a favorable combination of circumstances	the chance to speak

opportunity (verb)	say (verb)
	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