- water that contains magnesium, calcium, or iron salts and therefore forms a soap lather with difficulty.
Examples from the Web for hard water
Historical Examples of hard water
A French commissioner reported that apparently people in hard-water districts had a better physique than in soft-water districts.Rural Hygiene
Henry N. Ogden
These crispy croutons answer as a substitute for hard-water crackers and are also relished by most people.The Whitehouse Cookbook (1887)
Mrs. F.L. Gillette
Every drop of hard-water we consumed had to be brought to our doors and paid for by the “Hessian” or bucket.Recollections of Old Liverpool
Water in which dissolved minerals make it difficult to produce a lather with soap.