1. plural of furnace; enclosed structures in which fuel is burned to heat buildings or melt metals

Examples

• The old furnaces in the basement needed to be replaced.
• Steel furnaces operate at extremely high temperatures.
• Many homes switched from coal furnaces to gas heating systems.
• The factory’s furnaces ran continuously during production.
• Industrial furnaces are used to smelt iron ore.
• The apartment building had two large furnaces for heating.
• Modern furnaces are much more energy efficient than older models.