Bible Dictionaries
Hypocaust

Webster's Dictionary

(n.) A furnace, esp. one connected with a series of small chambers and flues of tiles or other masonry through which the heat of a fire was distributed to rooms above. This contrivance, first used in bath, was afterwards adopted in private houses.

Bibliography Information
Webster, Noah. Entry for 'Hypocaust'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​h/hypocaust.html. 1828.