selenium

noun

se·​le·​ni·​um sə-ˈlē-nē-əm 

: a photosensitive element that occurs in both crystalline and amorphous forms, is obtained chiefly as a by-product in copper refining, and is used especially in glass, semiconductor devices, and alloys see Chemical Elements Table

Examples of selenium in a Sentence

Recent Examples on the Web

The omega-3s from fatty fish like wild salmon play a key role in brain health and provide important nutrients like vitamin D, selenium, and zinc that support immune function and overall wellness, Gomes adds. —Randi Gollin, Martha Stewart, 22 Apr. 2026

Brazil Nuts Brazil nuts are best known for their high selenium content. —Abby Norman, Verywell Health, 21 Apr. 2026

Turkey breast is leaner than chicken breast, offering fewer calories and less fat while also delivering more B3, B12, choline, zinc, and selenium. —Jillian Kubala, Health, 15 Apr. 2026

The key mechanism lies in leveraging the relatively low melting point of selenium. —Prabhat Ranjan Mishra, Interesting Engineering, 9 Apr. 2026

Word History

Etymology

New Latin, from Greek selēnē moon, from selas brightness

First Known Use

1818, in the meaning defined above

Phrases Containing selenium

• selenium cell

Rhymes for selenium

• rhenium
• asplenium
• delphinium
• perineum
• proscenium
• ruthenium
• vaccinium

Kids Definition

selenium

noun

se·​le·​ni·​um sə-ˈlē-nē-əm 

: an element that is sensitive to light and is used especially in glass, alloys, and electronic devices see element

Medical Definition

selenium

noun

se·​le·​ni·​um sə-ˈlē-nē-əm 

: a nonmetallic photosensitive element that occurs in both crystalline and amorphous forms, is an essential trace element found especially in grains and meat, and is used chiefly in glass, semiconductor devices, and alloys

—symbol Se see Chemical Elements Table, selenosis