(1):

(n.) Witness; testimony; attestation.

(2):

(v. t.) To call to witness; to invoke.

(3):

(v. t.) 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.

(4):

(v. t.) To give proof of; to manifest; as, the ruins of Palmyra attest its ancient magnificence.