Search Result for "water softener":
Wordnet 3.0

NOUN (1)

1. a substance (such as sodium chloride) that lessens the hardness of water by replacing calcium and magnesium ions with sodium ions and so gives the water more efficient sudsing power; 



WordNet (r) 3.0 (2006):

water softener
    n 1: a substance (such as sodium chloride) that lessens the
         hardness of water by replacing calcium and magnesium ions
         with sodium ions and so gives the water more efficient
         sudsing power