se·​le·​ni·​um | \ sə-ˈlē-nē-əm How to pronounce selenium (audio) \

Definition of selenium

: 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 The chemicals in question: boron, selenium, cadmium and mercury. Sarah Bowman, Indianapolis Star, "IPL's Petersburg plant is the worst water polluter in state, violates permit 120 times," 8 June 2020 Packed with protein, chicken also provides a healthy dose of niacin, selenium and zinc, along with vitamins B6 and B12. Darlene Zimmerman, Detroit Free Press, "Chicken sheet pan dinners: Easy to make and a cleanup is a snap," 30 Apr. 2020 Morels also provide small amounts of potassium, magnesium, calcium, and selenium. Outdoor Life, "How to Hunt Morel Mushrooms Like Your Life Depends on It," 8 Apr. 2020 Specifically, the group says the creek has shown signs of elevated concentrations of mercury, and elevated levels of arsenic, molybdenum, selenium, copper and thallium from mining in the area. William Thornton |, al, "New Alabama mammoth mine project long in the making," 1 Mar. 2020 Truth be told, mushrooms supply several key nutrients including the B vitamins niacin, riboflavin, folate and B6, as well as iron, potassium, and selenium. Darlene Zimmerman, Detroit Free Press, "Risotto without rice: Here's how to use rice-shaped pasta instead," 19 Jan. 2020 Kanatzidis’s team combined lithium, indium, phosphorous, and selenium in a layered array of crystals. Caroline Delbert, Popular Mechanics, "Who Wouldn't Want a Pocket-Sized Neutron Detector?," 16 Jan. 2020 High levels of selenium can kill animals and cause them reproductive problems. Matthew Brown, San Diego Union-Tribune, "Pollution found in US river downstream of Canada mines," 23 Sep. 2019 While selenium is an essential nutrient at lower levels of exposure, high levels can disrupt the nervous system and cause kidney and heart failure, and even death. Travis Loller, Twin Cities, "Trump administration eases Obama-era rules on coal pollution," 4 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'selenium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of selenium

1818, in the meaning defined above

History and Etymology for selenium

New Latin, from Greek selēnē moon, from selas brightness

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Time Traveler for selenium

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The first known use of selenium was in 1818

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Statistics for selenium

Last Updated

11 Jun 2020

Cite this Entry

“Selenium.” Dictionary, Merriam-Webster, Accessed 8 Aug. 2020.

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More Definitions for selenium


How to pronounce selenium (audio)

English Language Learners Definition of selenium

technical : a chemical element that is used in electronic devices to make them sensitive to light


se·​le·​ni·​um | \ sə-ˈlē-nē-əm How to pronounce selenium (audio) \

Kids Definition of selenium

: a gray powdery chemical element used chiefly in electronic devices


se·​le·​ni·​um | \ sə-ˈlē-nē-əm How to pronounce selenium (audio) \

Medical Definition of selenium

: 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

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Rhyming Dictionary: Words that rhyme with selenium

Spanish Central: Translation of selenium

Nglish: Translation of selenium for Spanish Speakers Encyclopedia article about selenium

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