harden

verb
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 off harden 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 off plants hardened off before the first frost

Harden

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

Harden

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

concrete, congeal, firm (up), freeze, indurate, set, solidify

Antonyms: Verb

liquefy (also liquify), soften

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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

Trump manages to lie in ways that hardened cynics never anticipated. Jonathan Chait, Daily Intelligencer, "Did Trump Bribe Ukraine to Stop Cooperating With Mueller?," 2 May 2018 People need cholesterol to make hormones, vitamin D and other substances, but trouble arises when the waxy matter builds up inside the walls of arteries, hardening into plaque that restricts the flow of blood and increases the risk of heart disease. Jo Craven Mcginty, WSJ, "High Cholesterol? It Must Be January," 18 Jan. 2019 These services are expensive to build, test, and harden in real-world conditions, but once operational, are relatively inexpensive to scale to more games and more users. Kyle Orland, Ars Technica, "Epic opens Fortnite’s cross-platform services for free to other devs," 12 Dec. 2018 Butterfly caterpillars harden into chrysalises during their pupal stage. Kimberly Fornek, chicagotribune.com, "Western Springs business owner raises monarch butterflies and promotes conservation," 22 June 2018 All of those thoughts hardened into one resolution. Ryan Lenora Brown, The Christian Science Monitor, "For South Africa's students, college means promise – if they can get there," 23 Apr. 2018 The negotiation before the negotiation, their small talk hardening into chrome and steel. David Gilbert, The New Yorker, "Fungus," 4 June 2017 Serve immediately or place in a container to harden in the freezer to achieve hard-scoop ice cream texture. Priya Krishna, Marie Claire, "6 Boozy Frozen Drinks You Can Make at Home," 24 May 2017 To this end, the research community has worked to understand how to reduce the blind spots in ML systems so they can be hardened against attacks on those weaknesses. Lily Hay Newman, WIRED, "AI Can Help Cybersecurity—If It Can Fight Through the Hype," 29 Apr. 2018

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

Verb

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

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Statistics for harden

Last Updated

21 Apr 2019

Look-up Popularity

Time Traveler for harden

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

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More Definitions for harden

harden

verb

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

harden

verb
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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More from Merriam-Webster on harden

Rhyming Dictionary: Words that rhyme with harden

Thesaurus: All synonyms and antonyms for harden

Spanish Central: Translation of harden

Nglish: Translation of harden for Spanish Speakers

Britannica English: Translation of harden for Arabic Speakers

Comments on harden

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