furnace

noun

fur·​nace ˈfər-nəs How to pronounce furnace (audio)
: an enclosed structure in which heat is produced (as for heating a house or for reducing ore)

Examples of furnace in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Dropping off the ridges into the canyons was like descending into a furnace. — Jack Dolan, Los Angeles Times, 25 Aug. 2026 Similarly, when using the Heat setting, the HVAC system engages the furnace, boiler, or similar heating system at the same time as the fan, increasing the amount of energy used. — Timothy Dale, The Spruce, 24 Aug. 2026 It is used in cutting tools, drilling equipment, aerospace parts, furnaces and defense systems. — Atharva Gosavi, Interesting Engineering, 18 Aug. 2026 Reached by phone for comment, David Pimm, the president of the Bohemian National Cemetery Association, said two of the cemetery’s three retorts, or furnaces, were not working due to an electrical fire. — Gregory Royal Pratt, Chicago Tribune, 15 Aug. 2026 See All Example Sentences for furnace

Word History

Etymology

Middle English fourneyse, fornes, furneis "oven, kiln, furnace," borrowed from Anglo-French furneis, fornays, fornaise (continental Old French forneis —attested once as masculine noun— fornaise, feminine noun), going back to Latin fornāc-, fornāx (also furnāx) "furnace, oven, kiln (for heating baths, smelting metal, firing clay)," from forn-, furn-, base of furnus, fornus "oven for baking" + -āc-, -āx, noun suffix; forn- going back to Indo-European *gwhr̥-no- (whence also Old Irish gorn "piece of burning wood," Old Russian grŭnŭ, gŭrnŭ "cauldron," Russian gorn "furnace, forge," Bosnian-Croatian-Serbian gŕno "coals for heating iron at a smithy," Sanskrit ghṛṇáḥ "heat, ardor"), suffixed derivative of a verbal base *gwher- "become warm" — more at therm

Note: The variation between -or-, the expected outcome of zero grade, and -ur- in Latin has been explained as reflecting a rural/dialectal change of o to u, borrowing from Umbrian, or the result of a sound change of uncertain conditioning; see most recently Nicholas Zair, "The origins of -urC- for expected -orC- in Latin," Glotta, Band 93 (2017), pp. 255-89.

First Known Use

13th century, in the meaning defined above

Time Traveler
The first known use of furnace was in the 13th century

Phrases Containing furnace

Rhymes for furnace

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Browse Nearby Words

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Cite this Entry

“Furnace.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/furnace. Accessed 1 Sep. 2026.

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Kids Definition

furnace

noun
fur·​nace ˈfər-nəs How to pronounce furnace (audio)
: an enclosed structure in which heat is produced (as for heating a house or melting metals)

More from Merriam-Webster on furnace

Britannica.com: Encyclopedia article about furnace

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