'anything' originates from Old English, specifically the words 'ǣnig' (meaning 'any' or 'one') and 'þing' (meaning 'thing' or 'matter').

'anything' changed from the Old English compound 'ǣnig þing' into Middle English as 'any thing' and eventually became the single modern English word 'anything'.

Initially it meant 'any single thing' or 'any event/affair', and over time it kept that core sense while also being used more broadly to mean 'anything at all' (including informal plural uses like 'anythings').