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

The architectural project was overseen by international firm ACPV Architects Antonio Citterio Patricia Viel, preserving the storied chimney of the former furnace. —Luisa Zargani, Footwear News, 20 Oct. 2025

Informal salvage businesses buy old batteries and melt the lead in makeshift furnaces, releasing waste that ends up in the air, soil, and water. —Ben Smith, semafor.com, 17 Oct. 2025

The standard kit also has several floor and overhead storage solutions, including a front cabinet housing the 16,000-BTU furnace that helps the camper perform comfortably through winter. —New Atlas, 12 Oct. 2025

Residents who receive energy assistance may also be approved for a program that covers water heater or furnace repairs and replacements, Rodriguez said. —Francesca Pica, jsonline.com, 9 Oct. 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)