名词

1. excessive sternness

    e.g. severity of character
           the harshness of his punishment was inhuman
           the rigors of boot camp

    Synonym: severityseverenessharshnessrigorrigourrigorousnessrigourousnessinclemencystiffness

2. the quality of being difficult to do

    e.g. he assigned a series of problems of increasing hardness
           the ruggedness of his exams caused half the class to fail

    Synonym: ruggedness

3. devoid of passion or feeling
    hardheartedness

    Synonym: unfeelingnesscallousnesscallosityinsensibility

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

    e.g. the costs of reducing hardness depend on the relative amounts of calcium and magnesium compounds that are present

5. the property of being rigid and resistant to pressure
    not easily scratched
    measured on Mohs scale