1. An arched structure, usually of stone, brick, or concrete, forming the supporting structure of a ceiling or roof. 2. An arched overhead covering, such as the sky, that resembles the architectural structure in form. 3. A room or space, such as a cellar or storeroom, with arched walls and ceiling, especially when underground. 4. a bank vault. 5. A burial chamber, especially when underground. 6. An arched part of the body, especially the top part of the skull. 7. To construct or supply with an arched ceiling; cover with a vault. 8. To build or make in the shape of a vault; arch.
