vouch vs voucher

vouch is not a noun while voucher is a noun.

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

vouch (noun)	voucher (noun)
	a negotiable certificate that can be detached and redeemed as needed
	a document that serves as evidence of some expenditure
	someone who vouches for another or for the correctness of a statement

vouch (verb)	voucher (verb)
give supporting evidence
summon (a vouchee) into court to warrant or defend a title
give personal assurance; guarantee
give surety or assume responsibility