furnace
Americannoun
-
a structure or apparatus in which heat may be generated, as for heating houses, smelting ores, or producing steam.
-
a place characterized by intense heat.
The volcano was a seething furnace.
-
Astronomy. Furnace, the constellation Fornax.
verb (used with object)
noun
-
an enclosed chamber in which heat is produced to generate steam, destroy refuse, smelt or refine ores, etc
-
a very hot or stifling place
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of furnace
First recorded in 1175–1225; Middle English furneis, furnais, from Old French fornais, fournais, from Latin fornāc- (stem of fornāx “kiln, oven”), akin to formus “warm”
Explanation
A furnace is an appliance that heats houses and buildings by burning fuel or circulating hot water. Your furnace might rumble in the basement, sending heat up through your house's radiators. Most houses in cold climates have a furnace, to warm their rooms during the chilly months of the year. Furnaces also have industrial uses, like burning trash or extracting ore from metal. If someone says, "It's as hot as a furnace in this classroom!" they mean that it's extremely hot. Furnace comes from the Old French fornaise, "oven," with the Latin root word fornacem, "oven or kiln."
Vocabulary lists containing furnace
Mockingbird
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Unit 4: Powerful Openings
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Unit 1, Words to Know
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
An electric furnace steel mill consumes 40 megawatts to 200 megawatts of electricity during the course of a day, with power usage rising or falling based on the flow of steel production.
From The Wall Street Journal • Jun. 29, 2026
We are living through the era of the exploding rocket ships and the Cybertruck, and Twitter and Grok, the world’s most advanced money furnace.
From Salon • Jun. 22, 2026
It has a new pool, new roof, new windows and new furnace — but the six-bedroom house in Indianapolis has gotten exactly zero offers since it was put on the market two months ago.
From MarketWatch • May 13, 2026
I spent hours with Dad in our garage grease pit bleeding brakes, in our attic installing insulation, in the furnace room adjusting burners.
From The Wall Street Journal • May 2, 2026
Pouring out of the factories like black smoke from a furnace came the thousands of Negroes who worked there.
From "The Best of Enemies" by Osha Gray Davidson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
