IPA: /kəˈlɛf.ə.kə.tɔːr.i/
KK: /kæˈlɛfəkˌtɔri/
Relating to or causing warmth or heat.
The calefactory design of the building helps to keep it warm during winter.
A warm room in a monastery where people can sit and relax, often used for socializing or gathering.
The monks gathered in the calefactory to discuss their daily activities.
Calefactory is formed from "calefacere" (meaning to make warm) and the suffix "-ory" (meaning relating to or characterized by). The word refers to a place that is used for warming or heating.
Think of a place that 'makes warm' ('calefacere') — that's what a calefactory is, a space designed for heating.