'restrained' originates from the Latin word 'restringere,' where 're-' meant 'back' and 'stringere' meant 'to bind tightly.'

'restringere' transformed into the Old French word 'restreindre,' and eventually became the modern English word 'restrain' through Middle English.

Initially, it meant 'to bind back or hold in check,' and this meaning has largely remained the same in modern usage.