'attaint' originates from Old French, specifically the word 'ataindre' (or Anglo-French 'ataint'), ultimately from Latin 'attingere' where the prefix 'ad-' meant 'to/toward' and 'tangere' (or 'tingere') meant 'to touch'.

'attaint' changed from Old French 'ataindre' (and Anglo-French forms) into Middle English (e.g. 'attainten' or 'attaint') and eventually became the modern English 'attaint' (with legal senses such as 'to attaint' or the noun form referring to a stain or a record of attainder).

Initially it meant 'to touch or reach' (from Latin 'attingere'), but over time it evolved into legal and moral senses of 'to bring guilt on, to condemn' and the related sense of 'to stain or corrupt'.