to support as being true, certain, reliable, etc. (usually fol. by for )

Her record in office vouches for her integrity.

to attest; guarantee; certify (usually fol. by for )

to vouch for someone in a business transaction.

to sustain or uphold by, or as if by, practical proof or demonstration.

(formerly) to call or summon (a person) into court to make good a warranty of title.

to adduce or quote in support, as extracts from a book or author; cite in warrant or justification, as authority, instances, facts, etc.

Archaic . to warrant or attest; to support or authenticate with vouchers.

Archaic . to declare as with warrant; vouch for.

Obsolete . to call or take as a witness.

a vouching; an assertion.

a formal attestation; a supporting warrant.

verb

deny , disavow , refute , reject , renounce

verb

act as a witness , affirm , answer for , assert , asseverate , assure , attest to , avert , avow , back , bear testimony , be responsible for , certify , confirm , contend , corroborate , cosign , declare , get behind * , give an affidavit , guarantee , maintain , okay * , predicate , profess , prove , put forth , rubber-stamp , say so , sign for , sponsor , stand up for * , substantiate , support , swear to , swear up and down , testify , uphold , verify , vow , warrant , witness , attest , authenticate , aver , cite , endorse , establish