'undergo' originates from Old English, specifically the word 'underġān', where 'under' meant 'beneath' and 'ġān' meant 'to go'.

'underġān' transformed into the Middle English word 'undergon', and eventually became the modern English word 'undergo'.

Initially, it meant 'to go beneath or undergo something', but over time it evolved into its current meaning of 'to experience or endure something'.