<p><strong>Verb</strong></p><ul><li>(used with object)</li><li>certified</li><li>certify­ing</li><li>to attest as certain; give reliable information of; confirm: He certified the truth of his claim.</li><li>Synonyms: guarantee, validate, verify, corroborate</li><li>to testify to or vouch for in writing: The medical examiner will certify his findings to the court.</li><li>to guarantee; endorse reliably: to certify a document with an official seal.</li><li>to guarantee (a check) by writing on its face that the account against which it is drawn has sufficient funds to pay it.</li><li>to award a certificate to (a person) attesting to the completion of a course of study or the passing of a qualifying examination.</li><li>to declare legally insane and committable to a mental institution.</li><li>Archaic: to assure or inform with certainty.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object)</li><li>to give assurance; testify; vouch for the validity of something (usually followed by to).</li></ul>