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

Recent Examples on the Web
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.
The environments around neutron star collisions are thought to be the only furnaces in the cosmos extreme enough to generate elements like gold, silver and plutonium. —Robert Lea, Space.com, 20 July 2025 Can someone please turn off the heat furnace that's blasting Nashville? —Brad Schmitt, The Tennessean, 17 July 2025 Space heaters are ideal for heating a single room in the home, rather than forcing the furnace to work harder to increase the temperature throughout the entire house. —Timothy Dale, Better Homes & Gardens, 17 July 2025 But the upgrade ‒ new furnaces that run on a mix of hydrogen and natural gas rather than coal ‒ could have extended the plant's longevity. —Victoria Moorwood, The Enquirer, 2 July 2025 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

See All Rhymes for furnace

Browse Nearby Words

furn
furnace
furnace black
See all Nearby Words

Cite this Entry

“Furnace.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/furnace. Accessed 30 Jul. 2025.

Copy Citation

Share

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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

'Affect' vs. 'Effect'

Using Bullet Points ( • )

The Difference Between 'i.e.' and 'e.g.'

Democracy or Republic: What's the difference?
See More

Popular in Wordplay

See More

Our Best Historical Slang Terms

Even More Bird Names that Sound Like Insults (and Sometimes Are)

12 Lovely and Unusual Words for the Natural World

Better Ways to Say 'This Sucks'

8 Words with Fascinating Histories
See More

Popular

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Our Best Historical Slang Terms

Even More Bird Names that Sound Like Insults (and Sometimes Are)
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
anagrams on a chalk board
Word Builder Quiz Pick the letter that when added to a word will ma...
See All