cer·ti·fy / ˈsərtəˌfī/ • v. (-fies, -fied) [tr.] (often be certified) attest or confirm in a formal statement: | the medical witness certified that death was due to cerebral hemorrhage. ∎  [often as adj.] (certified) officially recognize (someone or something) as possessing certain qualifications or meeting certain standards: a certified scuba instructor. ∎  officially declare insane.

certify XIV. — (O)F. certifier — late or medL. certificāre, f. certus CERTAIN; see -FY.
So certification XV. certificate XV. — F. certificat or medL. certificātum, sb. use of pp. of certificāre; see -ATE 2.