be·​ryl·​li·​um bə-ˈri-lē-əm How to pronounce beryllium (audio)
: 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 Later that month electrical contract workers were exposed to hazardous beryllium dust while replacing lights. Abe Streep, Scientific American, 10 Nov. 2023 To double-check the finding, the researchers compared the date to beryllium levels – another chemical created by cosmic rays – in Greenland ice cores, and found confirmation. Matt Hrodey, Discover Magazine, 10 Oct. 2023 Paul Bierman’s laboratory at the University of Vermont dated the sample’s last time near the surface in a different way, using rare radioactive isotopes of aluminum and beryllium. Paul Bierman, Fortune, 24 July 2023 The molten salt will likely be a mixture of lithium fluoride and beryllium fluoride, known as FLiBe. IEEE Spectrum, 15 July 2023 The final beryllium mirror was a 6.5-meter array of 18 hexagonal beryllium mirrors, each weighing about 20 kilograms. IEEE Spectrum, 6 July 2022 The lithium nuclei would rapidly decay, first into beryllium and then into helium, and emit radiation. Mark Anderson, Discover Magazine, 22 Oct. 2012 The beryllium pieces, each coated with 0.12 ounce of gold, were designed to be exceptionally strong yet light at just 20 kilograms each. Chris Gunn, Scientific American, 1 Nov. 2021 The mine was originally developed for its beryllium in the 1980s with not much thought was given to the associated rare earth elements. Aldo Svaldi, The Denver Post, 12 Jan. 2020 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'beryllium.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin, from Greek bēryllion

First Known Use

circa 1847, in the meaning defined above

Time Traveler
The first known use of beryllium was circa 1847

Dictionary Entries Near beryllium

Cite this Entry

“Beryllium.” Dictionary, Merriam-Webster, Accessed 3 Dec. 2023.

Kids Definition


be·​ryl·​li·​um bə-ˈril-ē-əm How to pronounce beryllium (audio)
: a steel-gray light strong brittle toxic metallic element used chiefly to help harden alloys see element

Medical Definition


be·​ryl·​li·​um bə-ˈril-ē-əm How to pronounce beryllium (audio)
: a steel-gray light strong brittle toxic bivalent metallic element used chiefly as a hardening agent in alloys
symbol Be
see Chemical Elements Table

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