vouch vs secure

vouch is not an adjective while secure is an adjective.

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

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

Other hyponyms of vouch include bail, stipulate.

vouch (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

vouch (verb)	secure (verb)
give supporting evidence	make certain of
summon (a vouchee) into court to warrant or defend a title	cause to be firmly attached
give personal assurance; guarantee	fill or close tightly with or as if with a plug
give surety or assume responsibility	furnish with battens
	get by special effort
	assure payment of