adjective
hard
Containing a high level of dissolved minerals.
Hard water leaves a white deposit inside the kettle.
Etymology
Hard water was difficult to use with soap because dissolved minerals hinder lathering. The name came to identify water by that mineral content.
More examples
- Our tap water is quite hard.
- Soap lathers poorly in hard water.
- The filter reduces minerals in hard water.
Forms
hard
Similar words
- mineral-rich
- Describes the composition rather than its effects on soap.