magnesium oxide

noun

: a white highly infusible compound MgO used especially in refractories, cements, insulation, and fertilizers, in rubber manufacture, and in medicine as an antacid and mild laxative

Examples of magnesium oxide in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Magnesium salts like magnesium oxide are more likely to reduce iron absorption. — Jillian Kubala, Health, 2 Mar. 2026 Forms like magnesium citrate and glycinate are absorbed better than forms like magnesium oxide. — Morgan Pearson, Verywell Health, 21 May 2026 Its 12-inch-thick, commercial-grade walls are made of multiple layers of fire-resistant materials like magnesium oxide, sulfate boards and gypsum panels. — Sandra Barrera, Daily News, 14 Mar. 2026 The review found magnesium oxide supplements reduced bloating and abdominal discomfort for people with constipation. — Erica Sweeney, EverydayHealth.com, 14 Oct. 2025 See All Example Sentences for magnesium oxide

Word History

First Known Use

1866, in the meaning defined above

Time Traveler
The first known use of magnesium oxide was in 1866

Rhymes for magnesium oxide

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Browse Nearby Words

magnesium nitrate
magnesium oxide
magnesium oxychloride cement
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Cite this Entry

“Magnesium oxide.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/magnesium%20oxide. Accessed 8 Jul. 2026.

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Kids Definition

magnesium oxide

noun
: a white earthy solid that consists of magnesium and oxygen and is used especially in fertilizers and rubber, as a mild laxative, and against acid in the stomach

Medical Definition

magnesium oxide

noun
: a white highly infusible compound MgO used especially in refractories, cements, insulation, and fertilizers, in rubber manufacture, and in medicine as an antacid and mild laxative

More from Merriam-Webster on magnesium oxide

Britannica.com: Encyclopedia article about magnesium oxide

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