'avengement' originates from Old French, specifically the word 'avengier', where the form denoted taking vengeance or punishment.

'avengier' changed from Vulgar Latin '*advindicare' (an altered form influenced by Latin elements) and ultimately from Latin 'vindicare', and through Middle English forms the modern English noun 'avengement' was formed from the verb 'avenge'.

Initially, the root words referred broadly to 'claiming, vindicating, or punishing'; over time the sense narrowed to 'taking vengeance' and then to the noun meaning 'the act of taking vengeance' in modern usage.