authorize vs certify

authorize and certify both are verbs.

Word	Noun	Adjective	Verb	Adverb
authorize	No	No	Yes	No
certify	No	No	Yes	No

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

authorize (verb)	certify (verb)
grant authorization or clearance for	provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
give or delegate power or authority to	declare legally insane
	guarantee payment on; of checks
	guarantee as meeting a certain standard
	authorize officially