'unsatisfactorily' originates from the prefix 'un-' meaning 'not' and the word 'satisfactory,' which comes from Latin 'satisfacere,' where 'satis' meant 'enough' and 'facere' meant 'to do or make.'

'satisfacere' transformed into the Old French word 'satisfier,' and eventually became the modern English word 'satisfactory,' with 'un-' added to form 'unsatisfactory' and then 'unsatisfactorily.'

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