Term: soft water: water that is not hard (does not contain mineral salts that interfere with the formation of lather with soap)
Broader: 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 | Unrelated: antonym: a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other