'avowal' originates from Old French 'avouer', specifically the word 'avouer', where the elements ultimately derive from Latin roots 'ad-' and a root related to 'vow/declare' (see historical evolution).

'avowal' changed from Old French 'avouer' and Middle English forms such as 'avowen' and 'avowal' and eventually became the modern English noun 'avowal'.

Initially tied to the idea of openly declaring or asserting (related to calling or declaring), over time it came to mean a formal or frank declaration or a confession.