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

These fish have nutrients, such as omega-3 fatty acids, protein, selenium, vitamin D3, and B vitamins, which may help promote strong and healthy hair growth.3 Omega-3s are thought to have anti-inflammatory properties and protect hair follicles from damage. —Julie Marks, Verywell Health, 20 Mar. 2025

Sardines These small fish, especially when eaten whole, are a powerhouse of nutrients: Sardines contain vitamin D, selenium, and vitamin B12. —Alessandra Signorelli, Vogue, 11 Mar. 2025

Hedström and her team speculate that specific bioactive compounds in these types of fish, such as taurine and selenium, may play a role, as their antioxidant effects and positive influence on the body’s immune response may help protect nerve cells. —Tom Gavin, EverydayHealth.com, 4 Mar. 2025

Pepperoni Pepperoni contains protein, selenium, and vitamin K. —Elizabeth Barnes, Verywell Health, 4 Mar. 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