'madman' originates from Middle English, specifically the words 'mad' and 'man', where 'mad' meant 'insane' and 'man' referred to a male person.

'mad' changed from Old English word 'gemæd' and 'man' from Old English 'mann', eventually becoming the modern English word 'madman'.

Initially, it meant 'an insane man', and this meaning has largely remained the same in modern usage.