The definition of calcium is the fifth most abundant element in the human body.
See calcium in Webster's New World College Dictionary
Origin: ModL < L calx (gen. calcis), lime < or akin to Gr chalix, pebble + -ium: so named (1808) by Sir Humphry Davy
See calcium in American Heritage Dictionary 4
noun Symbol Ca
Origin: Latin calx, calc-, lime; see calx
Origin: + -ium.
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