'tax-free' originates from the combination of 'tax' and 'free', where 'tax' refers to a compulsory contribution to state revenue and 'free' means exempt or not subject to.

'tax-free' evolved from the Old English word 'tax' and the Middle English word 'fre', eventually forming the modern English term 'tax-free'.

Initially, it meant 'exempt from tax', and this meaning has largely remained the same in modern usage.