To solemnly declare verbally or in writing that a particular document or testimony about an event is a true and accurate representation of the facts; to bear witness to. To formally certify by a signature that the signer has been present at the execution of a particular writing so as to rebut any potential challenges to its authenticity.
v. 1) to confirm (usually in writing) that a document is genuine. 2) to bear witness that someone actually signed a document, such as a will. All states require at least two witnesses (three in Vermont) to attest that a will was signed and declared to be a will (except a will written in one's own handwriting in some states). (See: will, witness, holographic will)