'bombshell' originates from the combination of 'bomb' and 'shell', where 'bomb' meant 'explosive device' and 'shell' referred to the casing.

'bombshell' was used in the 17th century to describe an explosive projectile, and eventually became a metaphor for shocking news or a stunning person.

Initially, it meant 'an explosive device', but over time it evolved into its current meanings of 'shocking news' and 'attractive person'.