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magnesium oxide

American  

noun

Chemistry.
  1. magnesia.


magnesium oxide British  

noun

  1. Also called: magnesia.  a white tasteless substance occurring naturally as periclase: used as an antacid and laxative and in refractory materials, such as crucibles and fire bricks. Formula: MgO

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of magnesium oxide

First recorded in 1905–10

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Example Sentences

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The advice says drinking water high in minerals is better for constipation than tap water, and magnesium oxide supplements are good for improving symptoms.

From BBC Oct. 13, 2025

The magnesium formed a thin layer of magnesium oxide on the tantalum surface that appears to keep oxygen from getting through.

From Science Daily Feb. 5, 2024

That reaction would leave magnesium oxide powder, which when spread thin would rapidly react with CO2 from the atmosphere, re-forming magnesite, completing a cycle that could be repeated over and over.

From Science Magazine Sep. 3, 2020

When magnesium burns in air a white flaky ash of magnesium oxide is produced.

From Textbooks Feb. 14, 2019

The cement shall not contain more than 1.75% of anhydrous sulphuric acid, nor more than 4% of magnesium oxide.

From Transactions of the American Society of Civil Engineers, vol. LXX, Dec. 1910 Federal Investigations of Mine Accidents, Structural Materials and Fuels. Paper No. 1171 by Herbert M. Wilson

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