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

Use a wood or magnesium float to smooth the patching compound. — Tim Carter, Hartford Courant, 26 Sep. 2026

There is limited evidence that taking vitamin B12 and magnesium together increases energy levels. — Amy Brownstein, Verywell Health, 25 Sep. 2026

Arugula is rich in calcium, magnesium and vitamin K for bone health, along with fiber and plant compounds tied to cancer prevention and a healthier gut microbiome. — Hanna Wickes, Fort Worth Star-Telegram, 23 Sep. 2026

Reporter Melissa Stark said the brace weighs less than a pound and is made of magnesium, instead of titanium. — Pete Grathoff, Kansas City Star, 22 Sep. 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