The Collaborative International Dictionary
Hypocaust \Hyp"o*caust\, n. [L. hypocaustum, Gr. ?; ? under + ? to burn: cf. F. hypocauste.] (Anc. Arch.) 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.
Wiktionary
n. 1 An underfloor space or flue through which heat from a furnace passes to heat the floor of a room or a bath. 2 An underfloor heating system, even without such an underfloor space or flue, as adapted for modern housing.
Wikipedia
A hypocaust (Latin hypocaustum) was an ancient Roman system of underfloor heating, used to heat houses with hot air. The word derives from the Ancient Greek hypo meaning "under" and caust-, meaning "burnt" (as in caustic). The Roman Vitruvius, writing about the end of the 1st century BCE, attributes their invention to Sergius Orata.
Usage examples of "hypocaust".
So he turned his steps downward, edging back through the cellars of the Breadbox and the Assembly Hall, through the hypocaust, and so to a downshaft from the cellar of the Island of Butterflies that had escaped Bentick's notice.
Even the non-mageborn sasenna of the Church felt it, and as Antryg led them through boiler rooms and hypocausts and disused staircases, they kept looking behind them as if subliminally aware of the random stirrings Antryg could so clearly see moving in the gloom that closed in behind.
Even the non-mageborn sasenna of the Church felt it, and as Antryg led them through boiler rooms and hypocausts and disused stair.
Even the non-mageborn sasenna of the Church felt it, and as Antryg led them through boiler rooms and hypocausts and disused staircases, they kept looking behind them as if subliminally aware of the random stirrings Antryg could so clearly see moving in the gloom that closed in behind.