tessera (plural tesserae): Small piece of stone, glass,etc. used in making a mosaic.

See also: mosaic

tierceron: A major rib in a complex rib vault Tiercerons spring from the main springers.

See also: rib vault, springer
Other types of ribs: lierne, ridge, diagonal, transverse

transept: A rectangular area which cuts across the main axis of a basilica-type building and projects beyond it. The transept gives a basilica the shape of a Latin cross and usually serves to separate the main area of the building from an apse at the end.

Other parts of a church: ambulatory, apse, choir, crossing, east end, nave, west end

transverse arch: Supporting arch which runs across the vault from side to side, dividing the bays. it usually projects down from the surface of the vault.

Compare with transverse rib

transverse rib: The projecting bands which mark the transverse arches of a rib vault.

See also rib vault, springer.
Other types of ribs: lierne, ridge, diagonal, tierceron

trefoil: An ornamental form which has three lobes or foils.

Compare with: cinqfoil, quatrefoil

tribune or gallery: An upper story over the aisle which opens onto the nave or choir. It corresponds in length and width to the dimensions of the aisle below it.
Contrast with:triforium
See also: aisle, clerestory

triforium or triforium passage: A narrow passage in the thickness of the wall with arches opening onto the nave. It may occur at the level of the clerestory windows, or it may be located as a separate level below the clerestory. It may itself have an outer wall of glass rather than stone.

Contrast with gallery or tribune
See also: clerestory

trumeau: Vertical architectural member between the leaves of a doorway. Trumeaus were often highly decorated.

See also: jamb, trumeau figure

trumeau figure: Statue decorating a trumeau. Usually this was a human figure, very often a religious personage. .

See also: jamb figures, trumeau

twisted ribbon: An ornamental motif of thin, continuous bands arranged in in a rectilinear fashion, and represented as if the bands were three dimensional.
See also other repetative decorative motifs

tympanum (plural, tympana): The basically semicircular area enclosed by the arch above the lintel of an arched entranceway. This area is often decorated with sculpture in the Romanesque and Gothic periods.

See also: arch, lintel, portal