Definition of: certify

(sûr′tə·fī) v. ·fied, ·fy·ing v.t.
1. To give certain knowledge of; attest.
2. To assert as a matter of fact; assure.
3. To give a certificate of, as insanity.
—v.i.
4. To make attestation as to truth or excellence. [<F certifier <Med.L certificare attest <L certus certain + facere make]
—cer′ti·fi′a·ble adjective
—cer′ti·fi′er noun