spandrel

• POS: Noun
• HYPHEN: span=drel

CIDE DICTIONARY

spandrel, n. [From Span.].

•  The irregular triangular space between the curve of an arch and the inclosing right angle; or the space between the outer moldings of two contiguous arches and a horizontal line above them, or another arch above and inclosing them.  [1913 Webster]
•  A narrow mat or passe partout for a picture.  [1913 Webster]

OXFORD DICTIONARY

spandrel, n. Archit.
1 the almost triangular space between one side of the outer curve of an arch, a wall, and the ceiling or framework.
2 the space between the shoulders of adjoining arches and the ceiling or moulding above.

Idiom

spandrel wall a wall built on the curve of an arch, filling in the spandrel.

Etymology

perh. f. AF spaund(e)re, or f. espaundre EXPAND