Doubletree

(n.) The bar, or crosspiece, of a carriage, to which the singletrees are attached.

Thesaurus Entries

Easter sepulcher, ambry, apse, baptistery, blindstory, chancel, choir, cloisters, confessional, confessionary, cross bitt, crossarm, crossbar, crosspiece, crypt, diaconicon, diaconicum, doubletree, nave, porch, presbytery, rood loft, rood stair, rood tower, sacrarium, sacristy, singletree, swingletree, transom, transversal, transverse, traverse, triforium, vestry, whippletree