authenticate

/ə-ˈthen-ti-ˌkāt/

borrowed from Medieval Latin authenticātus, past participle of authenticāre "to stamp as genuine or authoritative," derivative of Latin authenticus "original (of documents)"

verb

  1. to prove or serve to prove to be real, true, or genuine

authenticate a document

confirm corroborate substantiate verify authenticate validate mean to attest to the truth or validity of something. confirm implies the removing of doubts by an authoritative statement or indisputable fact. corroborate suggests the strengthening of what is already partly established.