'deactivate' originates from the prefix 'de-' meaning 'reverse' or 'remove' and the word 'activate', which comes from Latin 'activare', meaning 'to make active'.

'activate' transformed from the Latin word 'activare' and eventually became the modern English word 'activate', with 'de-' added to form 'deactivate'.

Initially, it meant 'to reverse activation', and this meaning has largely remained the same in modern usage.