transitive verb.
To establish the authenticity of; prove genuine: synonym: confirm.
The Century Dictionary and Cyclopedia
To render authentic; give authority to by the proof, attestation, or formalities required by law or sufficient to entitle to credit.
To prove authentic; establish as correct or genuine.
To establish as true or worthy of belief: as, to authenticate a statement.
Authenticated.
the GNU version of the Collaborative International Dictionary of English
transitive verb.
To render authentic; to give authority to, by the proof, attestation, or formalities required by law, or sufficient to entitle to credit.
transitive verb.
To prove authentic; to determine as real and true.