三さん重じゅう水すい素そさんじゅうすいそMeanings1nountritiumScientific term for the radioactive isotope of hydrogen with mass number 3. Often referred to by the loanword トリチウム.See also: トリチウム三さん重じゅう水すい素そは水すい素その放ほう射しゃ性せい同どう