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

Johansson takes magnesium at night as part of a wind-down routine. — Samantha Agate, Charlotte Observer, 22 Aug. 2026

Reviewers concluded that magnesium supplementation was unlikely to deliver a clinically meaningful benefit for ordinary muscle cramps in older adults. — Samantha Agate, Fort Worth Star-Telegram, 21 Aug. 2026

Symbiotica’s high-dose liposomal supplements — vitamin C, magnesium and Irish moss sachets — sit alongside Neuromints adaptogen mints and H2 hydrogen tablets. — Ritu Upadhyay, Footwear News, 21 Aug. 2026

The company sources the magnesium from the Dead Sea, where magnesium chloride makes up 53 percent of the mineral content of the water. — Samantha Agate, Sacbee.com, 21 Aug. 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