con·firm / kənˈfərm/ • v. [tr.] 1. establish the truth or correctness of (something previously believed, suspected, or feared to be the case): if these fears are confirmed, the outlook for the economy will be dire. ∎  state with assurance that a report or fact is true: he confirmed that the general was in the hands of the rebels. ∎  (confirm someone in) reinforce someone in (an opinion, belief, or feeling): he fueled his misogyny by cultivating women who confirmed him in this view. ∎  make (a provisional arrangement or appointment) definite. ∎  make (something, esp. a person's appointment to a position or an agreement) formally valid; ratify. ∎  formally declare (someone) to be appointed to a particular position: he was confirmed as the new peace envoy.2. administer the religious rite of confirmation to: he had been baptized and confirmed.DERIVATIVES: con·firm·a·tive / -mətiv/ adj.con·firm·a·to·ry / -məˌtôrē/ adj.

confirm settle, establish XIII; administer confirmation to; strengthen, fortify XIV. — OF. confermer (later confirmer) — L. confirmāre, f. CON- (intensive) + firmāre strengthen, f. firmus FIRM.
So confirmation eccl. rite conveying special grace for the strengthening of the baptized; corroboration, ratification. XIV.