'anientise' originates from Middle French, specifically the word 'anéantir', where 'néant' meant 'nothing' (from Latin 'ne' + 'ens, entis' meaning 'being').

'anéantir' passed into Early Modern English as rare forms like 'aneantise/anientise' and eventually became the archaic English verb 'anientise'.

Initially, it meant 'to reduce to nothing,' and this sense has largely remained, though the verb has fallen into archaic and rare usage.