'pro-imprisonment' originates from the prefix 'pro-' meaning 'in favor of' and the word 'imprisonment' from Old French 'emprisoner', where 'en-' meant 'in' and 'prison' meant 'prison'.

'imprisonment' changed from the Old French word 'emprisoner' and eventually became the modern English word 'imprisonment'.

Initially, 'imprisonment' meant 'to put in prison', and this meaning has largely remained the same in modern usage.