ὑπόκαυστον
From LSJ
τὴν πρὶν ἐνεσφρήγισσεν Ἔρως θρασὺς εἰκόνα μορφῆς ἡμετέρης θερμῷ βένθεϊ σῆς κραδίης → the image of my beauty that bold Love earlier stamped in the hot depths of your heart
English (LSJ)
τό,
A the hot-air space under the sweating-room in a bathing establishment, hypocaust, Plin.Ep.2.17, Stat.Silv.1.5.59.