Tritium
/ˈtrɪtiəm/noun
A radioactive isotope of hydrogen with two neutrons.
Did you know?The name Tritium was coined in the 20th century from Latin tritium, meaning “the third,” because it is the third known isotope of hydrogen.
Etymological Timeline
Proto-Indo-European
PIE
*tréyes
“three”
Latin
Latin
tertius
“third”
Latin
Latin
tritium
“the third”
1920s
English
tritium
“the third isotope of hydrogen, later identified as radioactive hydrogen-3”
Modern English
English
tritium
“a radioactive isotope of hydrogen with two neutrons”