What is the meaning of 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.

To inform; to tell (a person) that something is true.

To assure (oneself) of something; to ascertain.

to pronounce dead; to attest, to declare one's death (by a doctor); to be attested, to be declared dead (by a doctor).

declare the death or decline of someone or something

Source: wiktionary.org