hard water

1. 1.

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

   Antonymssoft water

   Broaderwater

Questions about hard water

What does hard water mean?

hard water means "water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap".

What is the opposite of hard water?

The recorded antonyms are soft water.

Is hard water a common word?

hard water is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.