What is Attest?

Attest definition and meaning on Dictionary terms:
verb (used with object)
to bear witness to; certify; declare to be correct, true, or genuine; declare the truth of, in words or writing, especially affirm in an official capacity: to attest the truth of a statement.
to give proof or evidence of; manifest: His works attest his industry.
to put on oath.

verb (used without object)
to testify or bear witness (often followed by to): to attest to the reliability of an employee.

Archaic. witness; testimony; attestation.