Definitions of hardness
  1. noun
    the quality of being difficult to do
    “he assigned a series of problems of increasing hardness
    synonyms: ruggedness
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    type of:
    difficultness, difficulty
    the quality of being difficult
  2. noun
    the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
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    the property of giving little resistance to pressure and being easily cut or molded
    the property of being unyielding to the touch
    the property of being incompressible
    type of:
    body, consistence, consistency, eubstance
    the property of holding together and retaining its shape
  3. noun
    devoid of passion or feeling; hardheartedness
    synonyms: callosity, callousness, insensibility, unfeelingness
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    lack of sensibility
    type of:
    insensitiveness, insensitivity
    the inability to respond to affective changes in your interpersonal environment
  4. noun
    excessive sternness
  5. noun
    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”
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    type of:
    an essential and distinguishing attribute of something or someone
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