hard water

American  

noun

1. water that contains magnesium, calcium, or iron salts and therefore forms a soap lather with difficulty.

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hard water Cultural  

1. Water in which dissolved minerals make it difficult to produce a lather with soap.

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Hard water is usually associated with well water in regions where the rocks contain a large proportion of iron-bearing minerals.

Example Sentences

Other plastics, including ones promoted as highly recyclable, such as clear polyethylene bottles, which hold some medications, or hard water bottles, are being recycled at just 16%.

From Los Angeles Times • Jan. 14, 2026

As they evaporate and refill over time, Beeler said an alkali pool can be distinguished by a white ring — similar to hard water stains — that forms on exposed soil and rocks.

From Seattle Times • Feb. 16, 2023

But not everyone uses them, and they don’t address the impact of hard water on your home and appliances.

From Washington Post • Aug. 23, 2022

Over time, hard water can also cause problems with your appliances: "Hard water also decays pipes and adds wear and tear to your washer," says Dunphy.

From Salon • Aug. 19, 2022

Stones are hard, water is wet, objects unsupported fall toward the earth’s center.

From "1984" by George Orwell