un·der·croft (ŭndər-krôft′, -krŏft′)
A crypt, especially one used for burial under a church.
[Middle English : under-, under- + croft, crypt (from Middle Dutch crofte, from Medieval Latin crupta, from Latin crypta, crypt; see CRYPT).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.