A furnace is a device used to heat and melt materials, such as metal or glass. The crossword solutions for the term 'furnace' include STOVE (5 letters), SMITHY (6 letters), FORGE (5 letters), HEATER (6 letters), KILN (4 letters), INCINERATOR (11 letters), OVEN (4 letters), and OAST (4 letters). A STOVE is a device used for cooking and heating food, while a SMITHY is a workshop where blacksmiths work with metal. A FORGE is a furnace used to heat and shape metal, while a HEATER is a device used to warm a room or area. A KILN is a type of OVEN used to bake clay and other materials, while an INCINERATOR is a device used to burn waste. An OVEN is a device used to cook food, and an OAST is a KILN used to dry hops for beer brewing.