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tritium
noun
tri·ti·um
ˈtri-tē-əm
ˈtri-shē-
: 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
Radium continued to be used on military watches through the mid-20th century, and was finally phased out in favor of less dangerous tritium.
—
Oren Hartov, Robb Report, 13 June 2024
These require heavy forms of hydrogen—deuterium and tritium—for the fusion stage of the device, which is triggered by a plutonium or uranium fission bomb.
—
Siegfried S. Hecker, Foreign Affairs, 4 Dec. 2017
After that, four-digit Rolex dials use tritium luminescent paint, which typically loses its functionality after about 20 years.
—
Allen Farmelo, Robb Report, 7 May 2024
Notes & Opinions on 4-Digit Rolexes Rolex switched from radium to tritium in 1963.
—
Allen Farmelo, Robb Report, 7 May 2024
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These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tritium.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Word History
Etymology
New Latin, from Greek tritos third — more at third entry 1
First Known Use
1933, in the meaning defined above
Dictionary Entries Near tritium
Cite this Entry
“Tritium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tritium. Accessed 7 Jul. 2024.
Kids Definition
tritium
noun
tri·ti·um
ˈtrit-ē-əm
ˈtrish-ē-
: a rare radioactive form of hydrogen having atoms with three times the mass of ordinary light hydrogen atoms
Medical Definition
tritium
noun
tri·ti·um
ˈtrit-ē-əm
ˈtrish-ē-
: a radioactive isotope of hydrogen that has three times the mass of ordinary hydrogen
—symbol T
More from Merriam-Webster on tritium
Britannica.com: Encyclopedia article about tritium
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