hardness meaning and definition

HARDNESS noun

Definition of hardness (noun)

1. the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
   • antonym: softness
2. a quality of water that contains dissolved mineral salts that prevent soap from lathering
   • "the costs of reducing hardness depend on the relative amounts of calcium and magnesium compounds that are present"
3. devoid of passion or feeling; hardheartedness
   • synonyms: callosity, callousness, insensibility, unfeelingness
4. the quality of being difficult to do
   • "he assigned a series of problems of increasing hardness"; "the ruggedness of his exams caused half the class to fail"
   • synonyms: ruggedness
5. excessive sternness
   • "severity of character"; "the harshness of his punishment was inhuman"; "the rigors of boot camp"
   • synonyms: harshness, inclemency, rigor, rigorousness, rigour, rigourousness, severeness, severity, stiffness