confirm
/kən-ˈfərm/
verb
to give approval to : ratify
to make firm or firmer : strengthen
to administer the rite of confirmation to
confirm a treaty
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.