'unsurpassed' originates from the prefix 'un-' meaning 'not' and the verb 'surpass' meaning 'to exceed or go beyond'.

'Surpass' comes from the Old French word 'surpasser', which itself comes from the Latin 'super-' meaning 'above' and 'passus' meaning 'step'.

Initially, it meant 'not exceeded', and this meaning has remained consistent in modern usage.