'carefully-prepared' originates from the combination of 'carefully' and 'prepared', where 'carefully' is derived from 'care' meaning 'attention or caution' and 'prepared' from 'prepare' meaning 'to make ready'.

'carefully' evolved from the Old English word 'caru' meaning 'sorrow, anxiety' and 'prepared' from the Latin 'praeparare', meaning 'to make ready beforehand'.

Initially, 'carefully-prepared' meant 'made ready with caution', and this meaning has largely remained the same in modern usage.