'gradually' originates from Latin, specifically the word 'gradualis,' where 'gradus' meant 'step.' 'Slowed' comes from Old English 'slāwian,' meaning 'to become slow.'

'gradualis' transformed into the French word 'graduel,' and eventually became the modern English word 'gradual.' 'Slāwian' evolved into the Middle English 'slowen,' leading to the modern English 'slow.'

Initially, 'gradual' meant 'by steps,' and 'slow' meant 'not quick.' Over time, 'gradually-slowed' came to describe a process of deceleration.