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

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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.
Still, the World Traveler comes thoroughly outfitted and includes a Truma Combi Eco Plus furnace/water heater, the aforementioned air conditioner, a JBL Bluetooth stereo with speakers and a 24-in HD smart TV, all standard. —C.c. Weiss may 15, New Atlas, 15 May 2026 But unlike lower-commitment purchases like a car or an air fryer, a house doesn’t come with an owner’s manual, and every hollow whoosh through the vents meant the furnace was imploding or a pipe was bursting. —Maggie Slepian, Longreads, 14 May 2026 Other board members said the health impacts from pollution caused by gas water heaters and furnaces should be considered as costs also. —Paul Rogers, Mercury News, 13 May 2026 At the Koppel plant, an electric arc furnace is used to turn scrap metal into liquid steel. —Ricky Sayer, CBS News, 8 May 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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Cite this Entry

“Furnace.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/furnace. Accessed 22 May. 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

Nglish: Translation of furnace for Spanish Speakers

Britannica.com: Encyclopedia article about furnace

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