a radioactive isotope of hydrogen, occurring in trace amounts in natural hydrogen and produced in a nuclear reactor. Tritiated compounds are used as tracers. Symbol: T or 3H; half-life: 12.5 years
Word origin
C20: New Latin, from Greek tritos third
tritium in American English
(ˈtrɪtiəm)
noun
a radioactive isotope of hydrogen having an atomic weight of 3 and a half-life of c. 12.5 years: it decays by beta-particle emission and is used in thermonuclear bombs, thermonuclear fusion devices, as a radioactive tracer, etc.