'aspersion' originates from Latin, specifically the word 'aspersio', where 'ad-' (often assimilated to 'as-') meant 'to' and 'spergere'/'spargere' meant 'to sprinkle'.

'aspersion' changed from the Late Latin word 'aspersio' into Old/Middle French and Middle English forms (e.g. medieval English 'aspersioun') and eventually became the modern English word 'aspersion'.

Initially, it meant 'a sprinkling' (literal) but over time it developed a figurative sense of 'a smear or attack on reputation', which is common in modern usage.