
1) Medieval architecture 2) Type of arch
Found on
https://www.crosswordclues.com/clue/fan-vault

A fan vault is a form of vault used in the Gothic style, in which the ribs are all of the same curve and spaced equidistantly, in a manner resembling a fan. The initiation and propagation of this design element is strongly associated with England. The earliest example, dating from about the year 1351, may be seen in the cloisters of Gloucester Cat...
Found on
http://en.wikipedia.org/wiki/Fan_vault

(from the article `Gothic art`) ...of windows, an enlargement of windows to great proportions, and the conversion of the interior stories into a single unified vertical expanse. The ... ...no rival elsewhere in Europe. Nevertheless, other areas developed distinctive characteristics. The Perpendicular style is a phase of late Gothic ... ...
Found on
http://www.britannica.com/eb/a-z/f/7

resembles a fan! Constructed in concave ribs of equal length, which spring from a central point. The ribs meet, or nearly meet at the apex or crown of the vault.
Found on
http://www.encyclo.co.uk/local/20935

Form of vault made up of halved concave masonry cones decorated with blind tracery.
Found on
http://www.encyclo.co.uk/local/20941

Form of vault made up of halved concave masonry cones decorated with blind tracery.
Found on
http://www.encyclo.co.uk/local/22200

A vault which consists of fan-shaped half cones which usually meet at the center of a vault.
Found on
http://www.pitt.edu/~medart/menuglossary/INDEX.HTM
No exact match found.