hard water

Other forms: hard waters

Definitions of hard water

1. noun

   water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap
   antonyms:

   soft water

   water that is not hard (does not contain mineral salts that interfere with the formation of lather with soap)

   type of:

   H2O, water

   binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent