tri·​ti·​um | \ ˈtri-tē-əm How to pronounce tritium (audio) , ˈtri-shē- \

Definition of tritium

: a radioactive isotope of hydrogen that has one proton and two neutrons in its nucleus and that has three times the mass of ordinary hydrogen symbol T

Examples of tritium in a Sentence

Recent Examples on the Web Rebundle braiding hair also doesn't contain tritium, also known as triton. Ruth Samuel, Allure, 24 May 2021 Chinese records show that local power plants such as Daya Bay in Shenzhen also have released large amounts of tritium into the sea. Washington Post, 14 Apr. 2021 Otherwise the plant could quickly consume the world’s entire supply of tritium, which comes only from certain nuclear reactors. Adrian Cho, Science | AAAS, 19 Feb. 2021 So, researchers look at decaying tritium nuclei, focusing only on electrons with the highest energy. Don Lincoln, Forbes, 18 May 2021 Ian Fairlie, the former head of a U.K. government panel on radiation risks and an opponent of nuclear power, said Japan should add storage capacity for the water and wait for the tritium, which has a half-life of just over 12 years, to decay. James Whitlow Delano, WSJ, 11 Mar. 2021 Critics said the plant was antiquated and pointed to a safety history that included faulty reactor bolts and radioactive tritium detected in groundwater onsite. Michael Hill, Star Tribune, 29 Apr. 2021 Discharging wastewater into the sea is virtually the only way to deal with water contaminated by tritium—a radioactive hydrogen isotope that bonds with water. Eamon Barrett, Fortune, 16 Apr. 2021 Radiation experts have played down the fears about the water, too, suggesting that ingesting it would result in only a minute dose of radiation and that the tritium in the water would quickly pass through the body. Washington Post, 14 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tritium.' 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 tritium

1933, in the meaning defined above

History and Etymology for tritium

New Latin, from Greek tritos third — more at third entry 1

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Time Traveler for tritium

Time Traveler

The first known use of tritium was in 1933

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Statistics for tritium

Last Updated

16 Jun 2021

Cite this Entry

“Tritium.” Dictionary, Merriam-Webster, Accessed 18 Jun. 2021.

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More Definitions for tritium


tri·​ti·​um | \ ˈtrit-ē-əm How to pronounce tritium (audio) , ˈtrish-ē- How to pronounce tritium (audio) \

Medical Definition of tritium

: a radioactive isotope of hydrogen that has three times the mass of ordinary hydrogen symbol T

More from Merriam-Webster on tritium Encyclopedia article about tritium


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