Real Dictionary

vault
countable noun: A vault is a room underneath a church or in a cemetery where people are buried, usually the members of a single family.
countable noun: A vault is a secure room where money and other valuable things can be kept safely.
countable noun: A vault is an arched roof or ceiling.
verb: If you vault something or vault over it, you jump quickly onto or over it, especially by putting a hand on top of it to help you balance while you jump.

vault in American English 1
an arched roof, ceiling, or covering of masonry
intransitive verb: to curve or bend in the form of a vault
noun: an arched structure, usually made of stones, concrete, or bricks, forming a ceiling or roof over a hall, room, sewer, or other wholly or partially enclosed construction
transitive verb: to construct or cover with a vault

vault in American English 2
to jump, leap, or spring, as over a barrier or from one position to another, esp. with the help of the hands supported on the barrier, etc., or with the aid of a long pole
to vault over
intransitive verb: to leap or spring, as to or from a position or over something
noun: the act of vaulting
transitive verb: to leap over

vault in British English 1
noun: an arched structure that forms a roof or ceiling
verb: to furnish with or as if with an arched roof

vault in British English 2
noun: the act of vaulting
verb: to spring over (an object), esp with the aid of a long pole or with the hands resting on the object