magnesia

 
Pronunciation: /magˈniːʒə, -zɪə, -ʃə/

noun

[mass noun] Chemistry
  • magnesium oxide.
    • Chemical formula: MgO
  • hydrated magnesium carbonate used as an antacid and laxative.

Origin:

late Middle English (referring to a mineral said to be an ingredient of the philosopher's stone): via medieval Latin from Greek Magnēsia, denoting a mineral from Magnesia in Asia Minor