noun
tritium
A radioactive isotope of hydrogen with two neutrons; used in nuclear fusion and as a tracer.
トリチウムは水素の放射性同位体です。
Tritium is a radioactive isotope of hydrogen.
Radioactive isotope; tritium is one specific example.
Loanword from English 'tritium', derived from Greek 'tritos' meaning 'third', referring to the third isotope of hydrogen.