furnace
Americannoun
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a structure or apparatus in which heat may be generated, as for heating houses, smelting ores, or producing steam.
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a place characterized by intense heat.
The volcano was a seething furnace.
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Astronomy. Furnace, the constellation Fornax.
verb (used with object)
noun
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an enclosed chamber in which heat is produced to generate steam, destroy refuse, smelt or refine ores, etc
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a very hot or stifling place
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of furnace
First recorded in 1175–1225; Middle English furneis, furnais, from Old French fornais, fournais, from Latin fornāc- (stem of fornāx “kiln, oven”), akin to formus “warm”
Explanation
A furnace is an appliance that heats houses and buildings by burning fuel or circulating hot water. Your furnace might rumble in the basement, sending heat up through your house's radiators. Most houses in cold climates have a furnace, to warm their rooms during the chilly months of the year. Furnaces also have industrial uses, like burning trash or extracting ore from metal. If someone says, "It's as hot as a furnace in this classroom!" they mean that it's extremely hot. Furnace comes from the Old French fornaise, "oven," with the Latin root word fornacem, "oven or kiln."
Vocabulary lists containing furnace
Mockingbird
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
“There was this weird vent, a furnace return, and a tiny cabinet with a door above it,” said Pete Lauenstein.
From Los Angeles Times ● Jul. 21, 2026
A so-called "Salamander Tap" process can be used to temporarily shut down a blast furnace by drilling a hole to remove any remaining hot metal.
From BBC ● Jul. 17, 2026
Dr Deoras said: "This is not just a heatwave, it is a heat-dome driven furnace that will grip most of the southern UK and push temperatures into truly exceptional territory."
From BBC ● Jun. 24, 2026
Instead of working with a massive furnace, participants use small torches, making the process feel more approachable and easier to control.
From Salon ● Jun. 11, 2026
“Huh, it’s going to be as hot as the hell’s furnace, but at least it won’t rain,” he muttered aloud to himself.
From "Redwall" by Brian Jacques
It said the blast furnaces were "no longer financially sustainable," blaming "highly challenging" market conditions, tariffs and costs associated with moving to lower-carbon production techniques.
From BBC ● Jul. 17, 2026
This stopped its owner, Jingye, from closing blast furnaces, but the company remained privately owned.
From BBC ● Jul. 15, 2026
Rock samples are first heated in the furnaces to release volatile compounds.
From Science Daily ● Jul. 9, 2026
Electric arc furnaces are now the predominant method for making steel in the U.S.
From The Wall Street Journal ● Jun. 29, 2026
“The temperatures that we can reach with our furnaces will easily double what your blacksmiths can achieve.”
From "Strange the Dreamer" by Laini Taylor
Every word that he speaks has been fierily furnaced In the blast of a life that has struggled in earnest.
From Home Life of Great Authors by Griswold, Hattie Tyng
There he lies and sleeps From year to year—in soft Australian nights, And through the furnaced noons, and in the times Of wind and wet!
From The Poems of Henry Kendall With Biographical Note by Bertram Stevens by Kendall, Henry
And the winds blew with excessive heat, as if warmed by the breath of sighs furnaced forth by travellers grieved at being separated from their wives.
From Tales of the Sun or Folklore of Southern India by Kingscote, Mrs. Howard
Bake yourselves, kiln-dry yourselves, if you choose, in your furnaced houses at home, but, if you value your health, "reform that altogether" in Italy.
From The Atlantic Monthly, Volume 05, No. 31, May, 1860 by Various
Across a tract of furnaced flints there came a wind of water, From yellow banks with tender hints of Tethys' white-armed daughter.
From The Poems of Henry Kendall With Biographical Note by Bertram Stevens by Kendall, Henry
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
