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furnace

n. · v.
US //ˈfɝnəs// UK //fˈɜːnɪs// fur·nace
  1. 1 home heating system (n.)
    B2 Upper Intermediate American English

    a large machine, usually in a basement, that burns fuel to heat a whole building.

    an enclosed apparatus used to heat a building by circulating warm air or water through a system of vents or pipes.

    Example

    The furnace broke during the coldest week of winter, leaving the house freezing.

    Example

    The landlord promised to inspect the gas furnace before the first frost to ensure the heating system was operating at peak efficiency.

    Usage

    In British English, 'boiler' is the more common term for a domestic heating unit.
  2. 2 industrial heater (n.)
    C1 Advanced Technical Science

    a very hot container used for melting metal or making glass.

    an industrial structure or container designed to produce intense heat for processes such as smelting, refining, or glassmaking.

    Example

    Workers wore protective suits while pouring liquid metal from the furnace.

    Example

    The blast furnace remained operational twenty-four hours a day to maintain the extreme temperatures required for steel production.
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  1. 3 a very hot place (n.)
    B2 Upper Intermediate Informal

    a place that is uncomfortably hot.

    a location or environment characterized by oppressive or excessive heat.

    Example

    The office becomes a furnace in the afternoon when the sun hits the windows.

    Example

    Without a functioning air conditioning system, the top-floor apartment turned into a furnace during the July heatwave.
  2. 4 a difficult trial (n.)
    C2 Proficiency Literary

    a very difficult or painful experience that tests a person.

    a metaphorical place or period of severe trial, suffering, or intense discipline.

    Example

    The soldiers were changed forever by the furnace of the war.

    Example

    He emerged from the furnace of political scandal with his reputation damaged but his resolve significantly strengthened.
  3. 5 to heat (v.)
    C2 Proficiency Technical Science

    to heat something inside a furnace.

    to subject a material to intense heat within a furnace.

    Example

    The raw ore must be furnaced at high temperatures to extract the iron.

    Example

    The specialized ceramic components were furnaced for twelve hours to ensure they reached the necessary structural density.
Origin

From Middle English forneys, from Old French fornais (French fournaise), from Latin fornāx.

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