Webster's Revised Unabridged Dictionary · 1913

Attest

Attest ({not transcribed}) , transitive verb

[Latin attestari; ad + testari to bear witness: compare French attester.]

1.
To bear witness to; to certify; to affirm to be true or genuine; as, to attest the truth of a writing, a copy of record.
Facts... attested by particular pagan authors. — Addison
2.
To give proof of; to manifest; as, the ruins of Palmyra attest its ancient magnificence.
3.
To call to witness; to invoke. [Archaic]
The sacred streams which Heaven's imperial state Attests in oaths, and fears to violate. — Dryden

Attest , noun

Witness; testimony; attestation. [Rare]
The attest of eyes and ears. — Shakespeare