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

Test strips were again used to evaluate the hardness of the water once the testing period concluded. —Brittany Vanderbill, Better Homes & Gardens, 26 Nov. 2024

Quantum annealing: This term is borrowed from annealing, a process that uses heat to alter the physical or chemical properties of a metal, glass, or plastic film to increase ductility and reduce hardness. —Ars Technica, 30 Oct. 2024

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

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