Definitions for "Propylon"
The porch, vestibule, or entrance of an edifice.
(7) -- (pl. propyla) outer gateway; either an independent entrance building or an element in a wall, usually with a double door and columns supporting a porch on both fronts (Vermeule, 386) Sample Image (Lesson 20)
An enormous entrance built to protect the main artery in and out of an ancient city or sanctuary.