'stunner' originates from the English word 'stun,' which comes from the Old French word 'estoner,' meaning 'to astonish or daze.'

'estoner' transformed into the Middle English word 'stounen,' and eventually became the modern English word 'stun,' from which 'stunner' is derived.

Initially, it meant 'to astonish or daze,' but over time it evolved into its current meaning of 'a strikingly beautiful or impressive person or thing.'