hardness

noun

hard·​ness ˈhärd-nəs 

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

• hardship
• difficulty

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

The water’s mineral content and its softness or hardness comes into play with the fermenting process, Martin said. —Maggie Menderski, Louisville Courier Journal, 4 Sep. 2025

Its resistance to denting, measured by the Janka hardness scale, is about three to 10 times higher than common woods. —Georgina Jedikovska, Interesting Engineering, 2 Sep. 2025

Martin has a true hardness in his game, attacking the high-percentage areas and is an extremely physical player. —Corey Pronman, New York Times, 27 Aug. 2025

The column wheel is thermally blued, a process that not only enhances corrosion resistance but also increases surface hardness, and importantly - looks pleasing to the eye. —Matthew Catellier, Forbes.com, 22 Aug. 2025

Word History

First Known Use

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

Phrases Containing hardness

• Brinell hardness
• Brinell hardness number

Rhymes for hardness

• microhardness

Kids Definition

hardness

noun

hard·​ness ˈhärd-nəs 

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