Illustrated Architecture Dictionary
Church plan in the form of a Greek cross, with a square central mass and four arms of equal length.
The Greek-cross plan was widely used in Byzantine architecture and in Western churches inspired by Byzantine examples.
Greek cross: A cross with four equal arms
- A History of Architecture on the Comparative Method, by Sir Banister-Fletcher, New York, 1950, pp. 251-253
Examples on Buffalo Architecture & History Website: