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Webster 1913 Edition

Noun.

[

Under

+ Prov. E.

croft

a vault; cf. OD.

krochte

crypt, and E.

crypt

(Arch.)

A subterranean room of any kind; esp., one under a church (see

), or one used as a chapel or for any sacred purpose.

Noun.

A vault under the choir or chancel of a church; also, a vault or secret walk under ground.

undercroft ‎(plural undercrofts)