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

Whole eggs and egg yolks Low-carb protein powders: Unsweetened protein powders, such as whey and pea protein Meat, poultry, seafood, and eggs provide vitamins and minerals, like B12, iron, zinc, and selenium, all of which play important roles in health. —Jillian Kubala, Health, 9 June 2025

Tahini is high in protein, antioxidants, healthy fats, and contains essential minerals such as calcium, selenium, iron, and zinc. —Alessandra Signorelli, Vogue, 31 May 2025

Provides Antioxidants Sardines also offer selenium, a trace mineral that functions as a powerful antioxidant, said Routhenstein. —Kathleen Ferraro, Verywell Health, 28 May 2025

Dirt collected by a resident at the site showed selenium, a trace element that can be harmful in heavy concentrations, according to the results, which were reviewed by The Times. —Dakota Smith, Los Angeles Times, 28 Apr. 2025

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

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

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