furnace

noun

fur·​nace ˈfər-nəs 

: 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

Parker’s inspiration to create a heating furnace using gas was fueled by curiosity and cold winters in Morristown, New Jersey, where she was born and raised. — Sandra Guzmán, USA Today, 29 June 2026

The company could use an electric smelter to melt and purify the iron before feeding it into Gary’s existing oxygen furnaces or into the kind of electric arc furnace already built in Arkansas. — John Lippert, Chicago Tribune, 28 June 2026

Neglecting the Filter Whether your air conditioner is connected to the furnace and ductwork or is a stand-alone unit (such as a window AC or a mini-split system), changing the filter is necessary. — Timothy Dale, Better Homes & Gardens, 28 June 2026

Now, though, summer in the south is so brutal that centuries of architectural trickery is being outmatched, and in the north, houses designed to retain heat during the winter have become furnaces in sweltering summers. — Frank Andrews, CBS News, 25 June 2026

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 *g^whr̥-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 *g^wher- "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

Phrases Containing furnace

• blast furnace
• reverberatory furnace

Rhymes for furnace

• externus

Kids Definition

furnace

noun

fur·​nace ˈfər-nəs 

: an enclosed structure in which heat is produced (as for heating a house or melting metals)