Word: certify
To attest to (a fact) as the truth.
To authenticate or verify in writing.
To attest that a product, service, organization, or person has met an official standard. Example: These blankets have been certified as fireproof.
To inform; to tell (a person) that something is true.
To assure (oneself) of something; to ascertain.
You can find a list of possible crossword clues for CERTIFY below.