hard·​en | \ ˈhär-dᵊn How to pronounce harden (audio) \
hardened; hardening\ ˈhärd-​niŋ How to pronounce hardening (audio) , ˈhär-​dᵊn-​iŋ \

Definition of harden

 (Entry 1 of 3)

transitive verb

1 : to make hard or harder
2 : to confirm in disposition, feelings, or action especially : to make callous hardened his heart
3a : inure, toughen harden troops
b : to inure to unfavorable environmental conditions (such as cold) often used with offharden off seedlings before transplanting
4 : to protect from blast, heat, or radiation (as by a thick barrier or placement underground)

intransitive verb

1 : to become hard or harder
2a : to become firm, stable, or settled
b : to assume an appearance of harshness or severity her face hardened at the thought
3 : to become gradually acclimatized to unfavorable conditions often used with offplants hardened off before the first frost


biographical name (1)
Har·​den | \ ˈhär-dᵊn How to pronounce Harden (audio) \

Definition of Harden (Entry 2 of 3)

Sir Arthur 1865–1940 English chemist


biographical name (2)

Definition of Harden (Entry 3 of 3)

Maximilian 1861–1927 originally Felix Ernst Witkowski German writer

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Synonyms & Antonyms for harden

Synonyms: Verb

Antonyms: Verb

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Examples of harden in a Sentence

Verb The presence of certain substances in the blood can cause the arteries to harden. These additives are designed to harden the steel. substances that can harden the arteries The news has hardened opposition to the government. He had been hardened by his years of military service.
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Recent Examples on the Web: Verb Workers stood nearby as Schaaf looked through yellow goggles at the UV lights that harden the material for the panels. Sarah Ravani, SFChronicle.com, "Oakland factory 3-D prints small units to deliver faster, cheaper housing," 7 Nov. 2020 Constantly fact-checking conspiracy theories can harden the other side’s views or make people feel attacked. Charlie Warzel New York Times, Star Tribune, "How to talk to friends and family who share conspiracy theories," 26 Oct. 2020 Another danger is that Trump’s laissez-faire approach to the pandemic in recent months will only harden, even as a third wave of infections surges across the country. Matt Ford, The New Republic, "Trump Has Never Been More Dangerous Than He Is Now," 7 Nov. 2020 And mind you: This all has to happen quickly, otherwise the dough will harden. Priya Krishna, Bon Appétit, "I Never Thought to Make My Own Kaju Katli Until I Was Stuck at Home," 6 Nov. 2020 Natanz, built underground to harden it against airstrikes, long has been at the center of those fears since its discovery in 2002. NBC News, "Satellite photos reportedly show construction at Iran nuclear site," 28 Oct. 2020 Support in Scotland for breaking away from the rest of the U.K. climbed to a record as the coronavirus pandemic and economic fallout harden political divisions in the country. Alastair Reed, Bloomberg.com, "Scottish Independence Support Rises to Record in Divided U.K," 14 Oct. 2020 Twist the cutter, and the biscuit edges will harden. The Editors, Field & Stream, "The Best Recipes and Drinks for Hunting Camp," 10 Oct. 2020 Skin on the palms of the hands and soles of the feet may thicken or harden later in life. Megan Woodward, baltimoresun.com/maryland/carroll, "A Maryland toddler with a rare skin disorder regularly faces ‘traumatic stress.’ But she has devoted advocates: her parents.," 26 Oct. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'harden.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of harden


13th century, in the meaning defined at transitive sense 1

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Time Traveler for harden

Time Traveler

The first known use of harden was in the 13th century

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Statistics for harden

Last Updated

24 Nov 2020

Cite this Entry

“Harden.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harden. Accessed 27 Nov. 2020.

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More Definitions for harden


How to pronounce Harden (audio)

English Language Learners Definition of harden

: to become hard or firm or to make (something) hard or firm
: to become more definite and strongly felt or to make (something) more definite and strongly felt
: to make (someone) hard : to make (someone) less emotional and less likely to feel sorry for other people


hard·​en | \ ˈhär-dᵊn How to pronounce harden (audio) \
hardened; hardening

Kids Definition of harden

1 : to make or become hard or harder By now the cement has hardened.
2 : to make or become hardy or strong Years of tough work had hardened his muscles.
3 : to make or become stubborn or unfeeling She hardened her heart and refused to forgive him.

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Comments on harden

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