Entry 3 senses · 2 variants Webster, 1913 Calefactory · Cal·e·fac·to·ry · IPA a. n. 01 a. Making hot; producing or communicating heat. 1. Making hot; producing or communicating heat. 02 n. An apartment in a monastery, warmed and used as a sitting room. 1. An apartment in a monastery, warmed and used as a sitting room.(Eccl.) 2. A hollow sphere of metal, filled with hot water, or a chafing dish, placed on the altar in cold weather for the priest to warm his hands with.