A matroneum (plural: matronea; earlier also matronaeum, plural matronaea) in architecture is a gallery on the interior of a building, originally intended to accommodate women (whence the derivation from "matron").
In medieval churches matronea lost their function of accommodation and became purely architectonic elements, placed over the side aisles with the structural purpose of containing the thrust of the central nave, and came to consist solely of bays so placed.
In Early Gothic churches the matronea were one of the four elements which constituted the interior walls (arch, matroneum, triforium and clerestory), but they grew rare in the succeeding period of full-blown Gothic architecture