'badman' originates from English, specifically a compound of 'bad' + 'man', where 'bad' meant 'not good' and 'man' meant 'person' or 'male'.

'bad' (Old English/early Middle English roots meaning 'not good' or 'evil') combined with 'man' (Old English 'mann' meaning 'person') to form the compound 'badman' in Modern English; the plural followed the irregular plural pattern of 'man' → 'men', producing 'badmen'.

Initially, the components simply meant 'not good' + 'person'; over time the compound came to specifically denote a person of ill intent (a villain, criminal), a meaning largely retained in current usage.