"Refractory-lined" is a term commonly used in the context of industrial furnaces and kilns. Refractory materials are used to line these heating devices, providing insulation and protection against high temperatures. However, there are several synonyms for this term that can be used in communication to help express the same meaning. Some of the synonyms for "refractory-lined" include "heat-resistant," "fireproof," "insulated," "protected," and "thermal-resistant." These words help to convey the same idea that the heating device has a protective layer or material that can withstand high temperatures. Using these synonyms can help create more variation in language and make communication more engaging and exciting.