hardness

中文： 硬度、坚硬、艰难

1. The quality of being hard. (countable, uncountable)
2. An instance of this quality; hardship. (countable, uncountable)
3. The quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm). (countable, uncountable)
4. The resistance to scratching, cutting, indentation or abrasion of a metal or other solid material. (countable, uncountable)
5. The penetrating ability of electromagnetic radiation, such as x-rays; generally, the shorter the wavelength, the harder and more penetrating the radiation. (countable, uncountable)
6. The measure of resistance to damage of a facility, equipment, installation, or telecommunications infrastructure when subjected to attack. (countable, uncountable)
7. A measure of how hard a material is. (countable) · The hardness of the material was high.

复数 hardnesses