ˈ ̷ ̷ ̷ ̷+ˌkȯst noun
( -s )
Etymology: Latin hypocaustum, hypocauston, from Greek hypokauston, from neuter of hypokaustos heated by a hypocaust, from (assumed) Greek hypokaustos, verbal of Greek hypokaiein to light (a fire) under, from hypo- + kaiein to burn — more at caustic
: a central heating system of an ancient Roman dwelling, public bath, or other building consisting of an underground furnace or fire chamber and a series of tile flues for distribution of the heat