WordWeb Online

1. Established as genuine
   - authenticated, documented

1. Provide evidence for; stand as proof of; show by one's behaviour, attitude, or external attributes
   "His high fever attested to his illness"
   - certify, manifest, demonstrate, evidence
    
2. Authenticate, affirm to be true, genuine, or correct, as in an official capacity
   "I attest this signature"
    
3. Give testimony in a court of law
   - testify, take the stand, bear witness
    
4. Establish or verify the usage of
   "This word is not attested until 1993"

See also: attestant, attestation, echt, genuine

Type of: affirm, assert, aver, avow, bear witness, declare, evidence, prove, show, swan, swear, testify, verify