'disdainfully' originates from the Latin word 'disdignari,' where 'dis-' meant 'apart' and 'dignari' meant 'to deem worthy.'

'disdignari' transformed into the Old French word 'desdaigner,' and eventually became the modern English word 'disdain' through Middle English.

Initially, it meant 'to deem unworthy,' but over time it evolved into its current meaning of 'showing contempt or lack of respect.'