Spandril
SPANDRIL, or SPANDREL (formerly splaundrel, a word of unknown origin), in architecture, the space between any arch or curved brace and the level label, beams, etc., over the same. The spandrils over doorways in Perpendicular work are generally richly decorated. At Magdalen College, Oxford, is one which is perforated, and has a most beautiful effect. The spandril of doors is sometimes ornamented in the Decorated period, but seldom forms part of the composition of the doorway itself, being generally over the label.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)