What is the meaning of attest?

verb

• Provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes.
  • usage: "His high fever attested to his illness"; "The buildings in Rome manifest a high level of architectural sophistication"; "This decision demonstrates his sense of fairness"
  • synonyms: certify, manifest, demonstrate, evidence
• Authenticate, affirm to be true, genuine, or correct, as in an official capacity.
  • usage: "I attest this signature"
• Give testimony in a court of law.
  • synonyms: testify, take the stand, bear witness
• Establish or verify the usage of.
  • usage: "This word is not attested until 1993"