the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
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'
devoid of passion or feeling; hardheartedness
[ Syn: unfeelingness , callousness , callosity , insensibility ]
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
[ Syn: ruggedness ]
excessive sternness; severity of character; the harshness of his punishment was inhuman; the rigors of boot camp
[ Syn: severity , severeness , harshness , rigor , rigour , rigorousness , rigourousness , inclemency , stiffness ]