insure vs secure

insure is not an adjective while secure is an adjective.

Word	Noun	Adjective	Verb	Adverb
insure	No	No	Yes	No
secure	No	Yes	Yes	No

As verbs, insure and secure are synonyms defined as:

Other synonyms of insure include assure, ensure, guarantee.

insure (adjective)	secure (adjective)
	free from fear or doubt; easy in mind
	free from danger or risk
	not likely to fail or give way
	immune to attack; incapable of being tampered with
	financially safe

insure (verb)	secure (verb)
be careful or certain to do something; make certain of something	make certain of
protect by insurance	cause to be firmly attached
make certain of	fill or close tightly with or as if with a plug
take out insurance for	furnish with battens
	get by special effort
	assure payment of