hardnesses

Noun

hardness (countable and uncountable, plural hardnesses)

1. The quality of being hard.
   • Who can number the cloudes in wiſedom? or who can ſtay the bottles of heauen, / When the duſt groweeh^([sic – meaning groweth]) into hardneſſe and the clods cleaue faſt together?1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Job 38:37–38
2. An instance of this quality; hardship.
3. The quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm).
4. The resistance to scratching, cutting, indentation or abrasion of a metal or other solid material.
5. The penetrating ability of electromagnetic radiation, such as x-rays; generally, the shorter the wavelength, the harder and more penetrating the radiation.
6. The measure of resistance to damage of a facility, equipment, installation, or telecommunications infrastructure when subjected to attack.

See all 7 meanings of hardness