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

And of course, because this is a titanium Kickstarter multitool, there are also the obligatory slots for optional vials of glow-in-the-dark (and slightly radioactive) tritium. —Ben Coxworth, New Atlas, 30 Oct. 2024

While deuterium is very common and obtained from water, tritium is very rare. —Sophie Blondel, The Conversation, 18 Oct. 2024

The one most scientists prefer is deuterium plus tritium. —Sophie Blondel, The Conversation, 18 Oct. 2024

Siegfried Hecker, a former director of Los Alamos National Laboratory, believes the blasts included two uranium devices that would be suitable for tactical weapons, and one thermonuclear bomb that likely used tritium to boost its yield with a jolt of nuclear fusion. —Byrichard Stone, science.org, 23 Sep. 2024

Word History

Etymology

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

First Known Use

1933, in the meaning defined above

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