The word 'vault' entered English in the 14th century from the Old French 'voute' or 'vaute', meaning an arched roof or a turn. This Old French term itself descended from the Vulgar Latin 'volvita', a noun derived from the feminine past participle of the Latin verb 'volvere', meaning 'to roll' or 'to turn'. The core logic connecting the ancient root to the modern meanings lies in the concept of a turning or revolving motion. This evolved to describe a rounded, arched structure (as if formed by a turning motion), and later, by association with the shape of secure arched chambers, to a place for safekeeping. The verb sense 'to leap', first recorded in the 16th century, likely comes from the gymnastic feat of leaping over a horse or obstacle with the aid of the hands, mimicking a turning, arched motion of the body.

The modern English word 'vault' is a simplex form derived from a single, indivisible root.