'unrestriction' originates from the prefix 'un-' meaning 'not' and the word 'restriction' from Latin 'restrictio', where 're-' meant 'back' and 'stringere' meant 'to bind'.

'restrictio' transformed into the Old French word 'restriction', and eventually became the modern English word 'restriction', with 'un-' added to denote the opposite.

Initially, it meant 'not bound or limited', and this meaning has largely remained the same in modern usage.