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

Our furnace, water heater, deep freezer with food, CD collection, clothes, appliances; all that is downstairs is damaged. —Ben Steele, jsonline.com, 11 Aug. 2025

Such systems allow furnaces to operate closer to their optimal temperatures, cut waste, and extend asset life, thereby creating opportunities for emissions savings (assuming production levels remain constant). —Ankit Mishra, Forbes.com, 6 Aug. 2025

Christine Smith for decoration and coverings; The Harrison Brothers, Mark and Greg, for paint and renovation; Mark Thompson for the plumbing upgrade; Dwayne Thomas for the HVAC, furnace, and gas upgrade; Donny Clark for the electrical installation. —Lennie Omalza, The Courier-Journal, 17 July 2025

The first molten metal recently glided from one new three-story furnace, oozed down chutes and spilled into 26-foot casting cylinders, deep in the floor of the expansion. —Star Tribune, Chicago Tribune, 14 July 2025

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)