Meaning

noun a statement asserting the existence or the truth of something

noun the act of affirming or asserting or stating something

noun (religion) a solemn declaration that serves the same purpose as an oath (if an oath is objectionable to the person on religious or ethical grounds)

originFrom Old French afermacion, from Latin affirmare (“to assert”). Doublet of affirmatio.

Etymology from Wiktionary, CC BY-SA 3.0