Calcium (noun)

1. A chemical element with the symbol Ca and atomic number 20. It is a metallic element that is essential for the growth and maintenance of strong bones and teeth.
2. A compound of calcium, such as calcium carbonate or calcium chloride, used in many industrial and agricultural applications.

Origin:

The word "calcium" comes from the latin word "calx" which means lime. it was first used in english in the early 19th century.

Examples:

1. Calcium is an essential mineral for maintaining healthy bones.
2. Calcium supplements are often recommended for people with osteoporosis.
3. Calcium carbonate is commonly used as an antacid and a dietary supplement.
4. Calcium chloride is used as a de-icing agent on roads.
5. Calcium oxide is used in the production of cement.