The verb affirm has 3 senses (first 3 from tagged texts)
1. (9) 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. (3) affirm, verify, assert, avow, aver, swan, swear -- (to declare or affirm solemnly and formally as true; "Before God I swear I am innocent")