an underground room or vault, esp. beneath a church
Origin of undercroftMiddle English from under- (see under-) + croft, a vault from Medieval Latin crupta from Classical Latin crypta, crypt
A crypt, especially one used for burial under a church.
Origin of undercroftMiddle English under- under- croft crypt ( from Middle Dutch crofte ) ( from Medieval Latin crupta ) ( from Latin crypta crypt ; see crypt . )