'retrogression' originates from Latin, specifically the word 'retrogressio,' where 'retro-' meant 'backward' and 'gressio' meant 'a going.'

'retrogressio' transformed into the French word 'rétrogression,' and eventually became the modern English word 'retrogression' through Middle English.

Initially, it meant 'a going backward,' but over time it evolved into its current meaning of 'returning to an earlier, typically worse, state.'