[cer.ti.fy] vt -fied ; -fy.ing [ME certifien, fr. MF certifier, fr. LL certificare, fr. L certus certain--more at certain] (14c) 1: to attest authoritatively: as a: confirm b: to present in formal communication c: to attest as being true or as represented or as meeting a standard d: to attest officially to the insanity of
2: to inform with certainty: assure
3: to guarantee (a personal check) as to signature and amount by so indicating on the face
4: certificate, license -- cer.ti.fi.able adj -- cer.ti.fi.ably adv -- cer.ti.fi.er n syn certify, attest, witness, vouch mean to testify to the truth or genuineness of something. certify usu. applies to a written statement, esp. one carrying a signature or seal "certified that the candidate had met all requirements". attest applies to oral or written testimony usu. from experts or witnesses "attested to the authenticity of the document". witness applies to the subscribing of one's own name to a document as evidence of its genuineness "witnessed the signing of the will". vouch applies to one who testifies as a competent authority or a reliable person "willing to vouch for her integrity". syn see in addition approve