fan vault
noun
a vault composed of a number of concave conoidal surfaces, usually four, springing from the corners of the vaulting compartment and touching or intersecting at the top, often decorated with ribs.
Words nearby fan vault
fan mail,
fan palm,
fan roof,
fan the flames,
fan tracery,
fan vault,
fan vaulting,
fan window,
fan worm,
fan-tan,
fana