calcium

[ kal-see-uh m ]
/ ˈkæl si əm /

noun Chemistry, Biology.

a silver-white divalent metal, occurring combined in limestone, chalk, gypsum, etc., occurring also in vertebrates and other animals, as a component of bone, skeletal mass, shell, etc., and as a necessary element in nerve conduction, heartbeat, muscle contraction, and many other physiological functions. Symbol: Ca; atomic weight: 40.08; atomic number: 20; specific gravity: 1.55 at 20°C.

Origin of calcium

First recorded in 1800–10; calc- + -ium

Example sentences from the Web for calcium

British Dictionary definitions for calcium

calcium
/ (ˈkælsɪəm) /

noun

a malleable silvery-white metallic element of the alkaline earth group; the fifth most abundant element in the earth's crust (3.6 per cent), occurring esp as forms of calcium carbonate. It is an essential constituent of bones and teeth and is used as a deoxidizer in steel. Symbol: Ca; atomic no: 20; atomic wt: 40.078; valency: 2; relative density: 1.55; melting pt: 842±2°C; boiling pt: 1494°C

Word Origin for calcium

C19: from New Latin, from Latin calx lime

Medical definitions for calcium

calcium
[ kălsē-əm ]

n. Symbol Ca

A soft metallic element that is a basic component of animals and plants and constitutes approximately 3 percent of Earth's crust. It occurs naturally in limestone, gypsum, and fluorite. Atomic number 20.

Scientific definitions for calcium

calcium
[ kălsē-əm ]

Ca

A silvery-white, moderately hard metallic element of the alkaline-earth group that occurs in limestone and gypsum. It is a basic component of leaves, bones, teeth, and shells, and is essential for the normal growth and development of most animals and plants. Calcium is used to make plaster, cement, and alloys. Atomic number 20; atomic weight 40.08; melting point 842 to 848°C; boiling point 1,487°C; specific gravity 1.55; valence 2. See Periodic Table.