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

• adversity
• asperity
• difficulty
• hardship
• rigor

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

Consider Your Water's Hardness Level Water hardness also plays a role in when your sink should be cleaned. —Nafeesah Allen, Better Homes & Gardens, 5 Jan. 2025

Water hardness is determined by the amount of minerals present in your water. —Sherri Gordon, Health, 19 Dec. 2024

For all its ugliness, hardness is seductive, as is a toxic, dominating man’s pull. —Naomi Fry, The New Yorker, 30 Sep. 2024

Water hardness is created by minerals such as calcium carbonate. —Emiliano Tahui Gómez, Austin American-Statesman, 15 July 2024

Word History

First Known Use

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

Phrases Containing hardness

• Brinell hardness
• Brinell hardness number

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