hardness

noun

hard·​ness ˈhärd-nəs How to pronounce hardness (audio)
Synonyms of hardnessnext
1
: the quality or state of being hard
2
a
: the cohesion of the particles on the surface of a mineral as determined by its capacity to scratch another or be itself scratched compare mohs' scale
b
: resistance of metal to indentation under a static load or to scratching

Synonyms of hardness

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Examples of hardness in a Sentence

the hardness of a diamond The wood's hardness makes it suitable for carving.
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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.
Mechanical properties such as hardness and stiffness can help researchers understand how the protective layers respond to stresses and whether changes could affect fuel performance. — Neetika Walter, Interesting Engineering, 4 Sep. 2026 And with the hardness increasing exponentially as the numbers grow, no regular computers are likely to break RSA encryption anytime soon. — Peter Hall, Scientific American, 4 Sep. 2026 Different marbles vary in hardness, and regular cleaning, polishing, and sealing may be necessary—but some wear is inevitable. — Angelika Pokovba, Martha Stewart, 4 Sep. 2026 Notable changes include a rising demand for moissanite jewelry — a diamond alternative with similar hardness and a sparkly rainbow shine. — Footwear News, 2 Sep. 2026 See All Example Sentences for hardness

Word History

First Known Use

before the 12th century, in the meaning defined at sense 1

Time Traveler
The first known use of hardness was before the 12th century

Phrases Containing hardness

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Browse Nearby Words

hardmouthed
hardness
hardnose
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Cite this Entry

“Hardness.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hardness. Accessed 7 Sep. 2026.

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Kids Definition

hardness

noun
hard·​ness ˈhärd-nəs How to pronounce hardness (audio)
1
: the quality or state of being hard
2
: the ability of a substance (as a mineral) to scratch another substance or be itself scratched

More from Merriam-Webster on hardness

Britannica.com: Encyclopedia article about hardness

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