transept

UK: /ˈtrænsɛpt/ US: (tran′sept)

WordReference Random House Unabridged Dictionary of American English © 2025

tran•sept  (tran′sept), n. [Archit.]

1. any major transverse part of the body of a church, usually crossing the nave, at right angles, at the entrance to the choir.
2. an arm of this, on either side of the central aisle of a church.

• Anglo-Latin trānseptum. See trans-, septum
• 1530–40

tran•sep ′tal, adj. 
tran•sep ′tal•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

transept / ˈtrænsɛpt/ noun

1. either of the two wings of a cruciform church at right angles to the nave

Etymology: 16th Century: from Anglo-Latin transeptum, from Latin trans- + saeptum enclosure

tranˈseptal adjective