Meaning of 'hardness'

noun

excessive sternness

Synonyms: severity

noun

the quality of being difficult to do

Example: "They assigned a series of problems of increasing hardness."

Synonyms: ruggedness

noun

devoid of passion or feeling

Synonyms: unfeelingness callousness callosity insensibility

noun

a quality of water that contains dissolved mineral salts that prevent soap from lathering

Example: "the costs of reducing hardness depend on the relative amounts of calcium and magnesium compounds that are present"

noun

the property of being rigid and resistant to pressure