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

Fish and other lean protein sources, like poultry, beans, tofu, and eggs, also provide iron, zinc, vitamin B12, selenium, and magnesium, Petitpain said. —Stephanie Brown, Verywell Health, 15 June 2026

Sardines, however, provide significantly higher levels of nutrients per serving, among them omega-3 fatty acids, selenium, vitamin B12, plus calcium if eating bone-in options (totally safe to eat, as the canning process softens them to the texture of very al dente pasta). —Rebecca Firkser, Bon Appetit Magazine, 11 June 2026

Eggs may promote greater fullness due to their higher fat content and provide nutrients such as choline, vitamin A, and selenium. —Christina Manian, Health, 3 June 2026

For example, some shampoos contain selenium sulfide or pyrithione zinc to treat yeast overgrowth, while others contain ketoconazole. —Petra Guglielmetti, Glamour, 27 May 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
• 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