hardness
/ˈhɑɹdnəs/ noun B2- The quality of being hard.
- An instance of this quality; hardship.
- The quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm).
- The resistance to scratching, cutting, indentation or abrasion of a metal or other solid material.
- The penetrating ability of electromagnetic radiation, such as x-rays; generally, the shorter the wavelength, the harder and more penetrating the radiation.
- The measure of resistance to damage of a facility, equipment, installation, or telecommunications infrastructure when subjected to attack.
- A measure of how hard a material is. · The hardness of the material was high.
Plural hardnesses
From the library
There was something subtly wrong with the face, some coarseness of expression, some hardness, perhaps, of eye, some looseness of lip which marred its perfect beauty.
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