calcium

/ˈkælsi.əm/

IPA: /K AE1 L S IY0 AH0 M/

noun
  1. 1

    The chemical element (Symbol Ca), with an atomic number 20. It is a soft, silvery-white alkaline earth metal which occurs naturally as carbonate in limestone and as silicate in many rocks.

  2. 2

    An atom of this element.

Source: https://en.wiktionary.org/wiki/calcium