Triforium, the arcade over the arches of a church between the nave and side aisles. It is usually a dark gallery, being the wall-space against which the lean-to roof of the aisles rests. See GOTHIC ARCHITECTURE.
Triforium
Chambers's Encyclopaedia, Volume 10: Swastika to Zyrianovsk and Index, p. 293
Source scan(s): p. 0312