beryllium

noun

be·​ryl·​li·​um bə-ˈri-lē-əm 

: a chemical element of the alkaline earth metal group with atomic number 4 that occurs naturally in minerals such as beryl and is steel-gray in color, light and strong but brittle, and is used chiefly as a hardening agent in alloys see Chemical Elements Table

Examples of beryllium in a Sentence

Recent Examples on the Web

Some have been particularly alarmed by the presence of beryllium, a carcinogen that isn’t commonly tested for after wildfires. —Bloomberg, Mercury News, 11 Sep. 2025

Turn to the beryllium side and the neutrons are reflected. —David Szondy september 10, New Atlas, 10 Sep. 2025

That is, the process that (within the first three minutes after the big bang) produced the first light elements --- hydrogen, helium, and tiny amounts of lithium and beryllium. —Bruce Dorminey, Forbes.com, 12 Aug. 2025

In addition to the impending shipments of elevated radioactivity wastes from New York, Wayne Disposal, off I-94 near the Willow Run Airport in Wayne County's Van Buren Township, was receiving elevated-radioactivity wastes from another FUSRAP site, a long-shuttered beryllium plant in Luckey, Ohio. —Keith Matheny, Freep.com, 8 Aug. 2025

Word History

Etymology

New Latin, from Greek bēryllion

First Known Use

circa 1847, in the meaning defined above

Rhymes for beryllium

• concilium
• ileum
• lilium
• psyllium
• trillium
• penicillium
• verticillium

Kids Definition

beryllium

noun

be·​ryl·​li·​um bə-ˈril-ē-əm 

: a steel-gray light strong brittle toxic metallic element used chiefly to help harden alloys see element

Medical Definition

beryllium

noun

be·​ryl·​li·​um bə-ˈril-ē-əm 

: a steel-gray light strong brittle toxic bivalent metallic element used chiefly as a hardening agent in alloys

—symbol Be see Chemical Elements Table