# furnace

/ˈfɝnəs/ (US) · /fˈɜːnɪs/ (UK)

Source: https://englishreference.com/word/furnace
Updated: 2026-06-20

## Senses

### 1. home heating system

noun · CEFR B2 · American English

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

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

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

noun · CEFR C1 · Technical

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

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

- Workers wore protective suits while pouring liquid metal from the furnace.
- The blast furnace remained operational twenty-four hours a day to maintain the extreme temperatures required for steel production.

### 3. a very hot place

noun · CEFR B2 · Informal

a place that is uncomfortably hot.

For teachers: a location or environment characterized by oppressive or excessive heat.

- The office becomes a furnace in the afternoon when the sun hits the windows.
- Without a functioning air conditioning system, the top-floor apartment turned into a furnace during the July heatwave.

### 4. a difficult trial

noun · CEFR C2 · Literary

a very difficult or painful experience that tests a person.

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

- The soldiers were changed forever by the furnace of the war.
- He emerged from the furnace of political scandal with his reputation damaged but his resolve significantly strengthened.

### 5. to heat

verb · CEFR C2 · Technical

to heat something inside a furnace.

For teachers: to subject a material to intense heat within a furnace.

- The raw ore must be furnaced at high temperatures to extract the iron.
- The specialized ceramic components were furnaced for twelve hours to ensure they reached the necessary structural density.

## Examples

- The repairman came to fix the furnace before winter started.
- Workers at the steel mill must wear protective gear when they stand near the open furnace.
- The industrial furnace reached temperatures high enough to liquefy iron ore, allowing the molten metal to be poured into waiting molds for casting.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.