An Attestation

1. A thing that serves to bear witness, confirm, or authenticate; validation, verification, documentation.
2. A confirmation or authentication.
3. (business, finance) The process, performed by accountants or auditors, of providing independent opinion on published financial and other business information of a business, public agency, or other organization.
4. (linguistics, of a language, word, word form, or word meaning) An appearance in print or otherwise recorded on a permanent medium