(inorganic chemistry) 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.
(physics) 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.
“Experiments have shown that there is no definite relation between the hardness of the metal and its resistance to wearing by friction.”
“There were certainly no complaints about the hardness of the conditions on this occasion, even with a course that was practically waterlogged from the overnight rain.”
“Can one love a man despite the hardness of his demands?”
hardiness
The state of being hardy, especially (of a plant) of being resistant to cold or other environmental conditions.
“Despite facing intense scrutiny and criticism, she displayed remarkable hardihood, staying true to her convictions and standing up for what she believed in.”
“Facing numerous hardships and challenges, the young athlete displayed remarkable hardihood by pushing beyond her limits and achieving her goals.”
“Similarly, this finding leaves open the possibility that female characters expressed heroism in ways not entailing physical hardihood or risk.”
“Nerd immediately realised his tyres were frozen to the hardstand.”
“Along with an improved geographical position the new facility offers double the warehousing capacity and we now enjoy 2500m2 internal storage with an external hardstand area to handle FCL traffic.”
“To the side of the garage is a vehicular hardstand providing additional off road parking.”