magnesium

noun

mag·​ne·​sium mag-ˈnē-zē-əm 

-zhəm

: a silver-white malleable ductile light metallic element that occurs abundantly in nature and is used in metallurgical and chemical processes, in photography, signaling, and pyrotechnics because of the intense white light it produces on burning, and in construction especially in the form of light alloys see Chemical Elements Table

Examples of magnesium in a Sentence

Recent Examples on the Web

Green fireballs like the one Jenkins saw are often due to the presence of magnesium, which emits a bright blue-green light when heated and vaporized in the Earth's atmosphere, the museum said. —ABC News, 24 Mar. 2026

Dark chocolate is also a good source of magnesium. —Theara Coleman, TheWeek, 23 Mar. 2026

Rainbow-stemmed Swiss Chard adds a pop of color and dose of magnesium to ward off miserable migraines. —Catharine Kaufman, San Diego Union-Tribune, 20 Mar. 2026

Which high-protein breakfast, magnesium supplement, or skincare trend is best and why? —Mykenna Maniece, Vogue, 19 Mar. 2026

Word History

Etymology

New Latin, from magnesia

First Known Use

1812, in the meaning defined above

Phrases Containing magnesium

• magnesium carbonate
• magnesium chloride
• magnesium hydroxide
• magnesium oxide
• magnesium sulfate

Rhymes for magnesium

• caesium
• cesium
• trapezium

Kids Definition

magnesium

noun

mag·​ne·​sium mag-ˈnē-zē-əm 

-zhəm

: a silver-white metallic element that is light and easily worked, burns with a dazzling light, and is used in making lightweight alloys see element

Medical Definition

magnesium

noun

mag·​ne·​sium mag-ˈnē-zē-əm  -zhəm 

: a silver-white light malleable ductile metallic element that occurs abundantly in nature (as in bones and seeds and in the form of chlorophyll in the green parts of plants) and is used in metallurgical and chemical processes, in photography, in signaling, and in the manufacture of pyrotechnics because of the intense white light it produces on burning, and in construction especially in the form of light alloys

—symbol Mg see Chemical Elements Table