from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A rare radioactive hydrogen isotope with atomic mass 3 and half-life 12.5 years, prepared artificially for use as a tracer and as a constituent of hydrogen bombs.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A radioactive isotope of the element hydrogen, (symbol T or 31H), having one proton and two neutrons.
- n. An atom of this isotope.
from the GNU version of the Collaborative International Dictionary of English
- n. A radioactive isotope of hydrogen having one proton and two neutrons in the nucleus. It decays spontaneously to Helium-3 by the emission of an electron (beta ray), with a half-life of 12.3 years. Symbol 1H3. Atomic weight 3.01605 (C-12 = 12.0000). It is one of the radioisotopes commonly used to label chemical compounds for use as tracers in biochemistry and chemistry. It is also used as one of the fusionable components of a hydrogen bomb.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms
From Greek tritos, third; see trei- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Ancient Greek τρίτος (tritos, "third") + -ium. (Wiktionary)