selenium

/səˈliniəm/
noun
  1. A chemical element that is a nonmetal, found in small amounts in soil and some foods, and important for human health.
    • Selenium helps protect the body from damage caused by free radicals.
    • Brazil nuts are one of the richest natural sources of selenium.
    • Farmers sometimes add selenium to animal feed to keep livestock healthy.
  2. A gray or red solid form of this element used in electronics, glassmaking, and photocopiers.
    • Some early solar cells were made with selenium instead of silicon.
    • Old photocopiers used a drum coated with selenium to transfer images.
    • Selenium is added to glass to remove green color or to make red glass.