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  • harden
    harden
    verb (used with object)
    to make hard or harder.
  • Harden
    Harden
    noun
    Sir Arthur, 1865–1940, English biochemist: Nobel Prize 1929.
Synonyms

harden

1 American  
[hahr-dn] / ˈhɑr dn /

verb (used with object)

  • hardens,
    present (3rd person singular)
  • hardened,
    past participle,  past
  • hardening
    present participle
  1. to make hard or harder.

    to harden steel.

    Synonyms:
    ossify, petrify, indurate, solidify
    Antonyms:
    soften
  2. to make pitiless or unfeeling.

    to harden one's heart.

  3. to make rigid or unyielding; stiffen.

    The rigors of poverty hardened his personality.

  4. to strengthen or confirm, especially with reference to character, intentions, feelings, etc.; reinforce.

    Synonyms:
    nerve, brace, steel, fortify
    Antonyms:
    weaken
  5. to make hardy, robust, or capable of endurance; toughen.

  6. Military. to reinforce the structure of (a military or strategic installation) to protect it from nuclear bombardment.


verb (used without object)

  • hardens,
    present (3rd person singular)
  • hardened,
    past participle,  past
  • hardening
    present participle
  1. to become hard or harder.

  2. to become pitiless or unfeeling.

  3. to become rigid or unyielding; stiffen.

    His personality hardened over the years.

  4. to become confirmed or strengthened.

    His resistance hardened.

  5. to become inured or toughened.

    The troops hardened under constant fire.

  6. Commerce. (of a market, prices, etc.)

    1. to cease to fluctuate; firm.

      When the speculators withdrew from the market, the prices hardened.

    2. to rise higher.

Harden 2 American  
[hahr-dn] / ˈhɑr dn /

noun

  1. Sir Arthur, 1865–1940, English biochemist: Nobel Prize 1929.


harden 1 British  
/ ˈhɑːdən /

verb

  1. to make or become hard or harder; freeze, stiffen, or set

  2. to make or become more hardy, tough, or unfeeling

  3. to make or become stronger or firmer

    they hardened defences

  4. to make or become more resolute or set

    hardened in his resolve

  5. (intr) commerce

    1. (of prices, a market, etc) to cease to fluctuate

    2. (of price) to rise higher

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

harden 2 British  
/ ˈhɑːdən /

noun

  1. a rough fabric made from hards

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of harden

Middle English word dating back to 1150–1200; see origin at hard, -en 1

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.

See Examples For:

He said that evidence from a U.S. bout of high inflation in the 1970s shows that a series of shocks that raise prices can harden over time into permanently higher inflation.

From MarketWatch Jul. 31, 2026

The projections harden into commitments that become harder to walk back.

From The Wall Street Journal Jun. 15, 2026

The drone attack is also likely to harden the stance of the UAE, which has grown increasingly hawkish since the war began.

From Barron's May 18, 2026

The impact of this, he said, is Israeli troops "having to move more cautiously, harden positions, use physical protective measures such as nets and cages, and devote more attention to immediate local defence".

From BBC May 16, 2026

Then he balls his fists and I watch his skin harden into metal.

From "Amari and the Night Brothers" by B.B. Alston

He and Harden were two of their top three scorers.

From Los Angeles Times Jun. 21, 2026

Brown knew that Brunson was among the best one-on-one scorers in the NBA, and that Cleveland guard James Harden was notoriously slow-footed on defense.

From The Wall Street Journal May 20, 2026

The Knicks set screens to force Harden to switch onto Brunson—and then got out of the way to let their leader go to work.

From The Wall Street Journal May 20, 2026

The member of the public called for an ambulance himself and, along with Matabiswana's girlfriend, administered first aid to an unresponsive Harden.

From BBC May 18, 2026

“Madam, Mrs. Harden says she has sent up the usual quantity.”

From "Jane Eyre" by Charlotte Brontë

Volcanoes form when molten rock from Earth's mantle rises to the surface and hardens.

From Science Daily Jul. 10, 2026

Before, Ahmad could tap — meaning to cut incisions in the acacia trees, which exude sap that a few weeks later hardens into nodules of Hashab gum — four orchards in one go.

From Los Angeles Times May 31, 2026

The sun hardens up the clay and creates a faster surface that generally favours bigger servers, more aggressive returners and players who hit with top-spin.

From BBC May 26, 2026

If it hardens, Apple is renting its future.

From MarketWatch Apr. 22, 2026

The pupa hardens into a weather-resistant package that can lie dormant for weeks or months.

From "The Girl Who Drew Butterflies: How Maria Merian's Art Changed Science" by Joyce Sidman

Under the company’s framework, a model reaches the “critical” cybersecurity threshold if it can autonomously find and exploit vulnerabilities, or carry out end-to-end cyberattacks against hardened targets with only high-level instructions.

From The Wall Street Journal Aug. 7, 2026

Confidential,’” says Chhiu of the stunts in “Spider-Noir,” which follows Cage as a hardened private detective confronting the criminal underbelly of 1930s New York.

From Los Angeles Times Aug. 5, 2026

These weapons allow the US to conduct precision strikes against hardened military targets, such as command bunkers or fortified military facilities, without putting manned aircraft in harm's way.

From BBC Jul. 27, 2026

"The hawkish core of the Fed has not only hardened but it's broadened," said Swonk, who expects two rate hikes later this year.

From Barron's Jul. 26, 2026

Its thin leather strap stretched from being fastened around the waist to the last hole, and was now a hardened leather with a blinding, mean snap.

From "P.S. Be Eleven" by Rita Williams-Garcia

It marks a wider trend of governments hardening their stance on undocumented migration, with many, including the UK and Italy, adopting measures aimed at deterring it.

From BBC Jul. 4, 2026

Horvath said the county hopes to receive tens of millions of dollars in state funding for additional brush clearance, fuel modification, home hardening and other initiatives.

From Los Angeles Times Jun. 26, 2026

UV light is used for air purification, curing resins in 3D printing, hardening gels in dental fillings, and even applications such as nail treatments.

From Science Daily Jun. 26, 2026

The head of Nevada’s welfare department, George Miller, was hardening his agency into a national model for a more-aggressive approach.

From The Wall Street Journal Jun. 5, 2026

The striped canvas sides of the tent stiffen, the soft surface hardening as the fabric changes to paper.

From "The Night Circus" by Erin Morgenstern

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