'maddening' originates from the verb 'madden', which comes from the Old English word 'gemæddian', where 'ge-' was a prefix used to form verbs and 'mæddian' meant 'to make mad'.

'gemæddian' transformed into the Middle English word 'madden', and eventually became the modern English word 'madden'.

Initially, it meant 'to make someone insane', but over time it evolved into its current meaning of 'extremely annoying or infuriating'.