vouch
intransitive verbTo give personal assurances or a guarantee.
intransitive verbTo constitute supporting evidence; give substantiation.
intransitive verbTo substantiate by supplying evidence; prove.
intransitive verbTo summon (someone) as a witness to give warranty of title.
intransitive verbTo refer to (an authority, for example) in support or corroboration; cite.
intransitive verbTo assert; declare.
nounA declaration of opinion; an assertion.
nounApproving or supporting warrant; confirmation; attestation.
To call to witness.
To declare; assert; affirm; attest; avouch.