Examples from the Web for undercroft
Two heavy wooden doors at the entrance leave no doubt as to the purpose for which the undercroft was built.
The canopy is gone, but fragments of it are in the undercroft of the chapter-house.
In the undercroft itself the walls are impregnably thick, the windows narrow, with wide splays.
This crypt or undercroft is on the same level as the floor of the church, and was used as a treasury.The Cathedrals of Great Britain|P. H. Ditchfield
The ancient history of this undercroft is unknown, and merely a matter for conjecture.The Old Inns of Old England, Volume II (of 2)|Charles G. Harper