facility vs hardness

facility

noun
  • The fact of being easy, or easily done; absence of difficulty, simplicity. 

  • Dexterity of speech or action; skill, talent. 

  • An institution specially designed for a specific purpose, such as incarceration, military use, or scientific experimentation. 

  • A toilet. 

  • The physical means or contrivances to make something (especially a public service) possible; the required equipment, infrastructure, location etc. 

  • A condition of mental weakness less than idiocy, but enough to make a person easily persuaded to do something against their better interest. 

hardness

noun
  • The quality of being hard. 

  • An instance of this quality; hardship. 

  • 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 quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm). 

How often have the words facility and hardness occurred in a corpus of books? (source: Google Ngram Viewer )