The verb confirm has 5 senses (first 4 from tagged texts)
1. (19) confirm, corroborate, sustain, substantiate, support, affirm -- (establish or strengthen as with new evidence or facts; "his story confirmed my doubts"; "The evidence supports the defendant")
2. (5) confirm, reassert -- (strengthen or make more firm; "The witnesses confirmed the victim's account")
3. (2) confirm -- (make more firm; "Confirm thy soul in self-control!")
4. (1) confirm -- (support a person for a position; "The Senate confirmed the President's candidate for Secretary of Defense")
5. confirm -- (administer the rite of confirmation to; "the children were confirmed in their mother's faith")