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

Relevance
See All Synonyms & Antonyms in Thesaurus

Examples of hardness in a Sentence

the hardness of a diamond The wood's hardness makes it suitable for carving.
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.
Chrysoberyl is a rare gemstone prized for its exceptional hardness and brilliance, known for its honey and chartreuse hues that shift under the light, making Khaled’s one-of-a-kind watch shine that much brighter. — Taylor Stoddard, Robb Report, 21 Oct. 2026 Tooth enamel is the hardest substance in the human body, measuring about 5 on the Mohs hardness scale, which is higher than some types of iron and steel, according to the Cleveland Clinic. — Ryan Brennan, Miami Herald, 20 Oct. 2026 Given the hardness of the wall surfaces and unique sloping design, mounting larger frames would be difficult, possibly even disastrous. — Wendy S. Walters, Architectural Digest, 12 Oct. 2026 There was real contrast to the elements of Watts’ look, which ultimately took boho-style pieces and juxtaposed them with the hardness of leather material. — Julia Teti, Footwear News, 5 Oct. 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

Rhymes for hardness

See All Rhymes for hardness

Browse Nearby Words

hardmouthed
hardness
hardnose
See all Nearby Words

Cite this Entry

“Hardness.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hardness. Accessed 27 Oct. 2026.

Copy Citation

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

Love words? Need even more definitions?

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

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of milieu

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

12 Lovely and Unusual Words for the Natural World

Why do we 'bury the lede?'

'Za' and 9 Other Words to Help You Win at SCRABBLE
See More

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
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?
The Missing Letter A daily crossword with a twist
different halloween monsters in silhouette
A Monstrous Vocab Quiz Words That Go Bump in the Night
See All