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[doo-teer-ee-uh m, dyoo-] /duˈtɪər i əm, dyu-/
noun, Chemistry.
an isotope of hydrogen, having twice the mass of ordinary hydrogen; heavy hydrogen. Symbol: D; atomic weight: 2.01; atomic number: 1.
Origin of deuterium
1933; < Greek deúter(os) second (see deutero-) + -ium Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the Web for deuterium
Contemporary Examples
Historical Examples
  • Then, for a considerably higher price, he would undertake to collect a sample of the deuterium they were using.

    The Caves of Fear John Blaine
  • Well, heavy water is made of one atom of oxygen plus two atoms of deuterium, which is the first isotope of hydrogen.

    The Caves of Fear John Blaine
British Dictionary definitions for deuterium


a stable isotope of hydrogen, occurring in natural hydrogen (156 parts per million) and in heavy water: used as a tracer in chemistry and biology. Symbol: D or ²H; atomic no: 1; atomic wt: 2.014; boiling pt: –249.7°C
Word Origin
C20: New Latin; see deutero-, -ium; from the fact that it is the second heaviest hydrogen isotope
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for deuterium

1933, coined by U.S. chemist Harold C. Urey, with Modern Latin ending + Greek deuterion, neuter of deuterios "having second place," from deuteros "second," from duo (see two). So called because it is twice the mass of hydrogen.

Online Etymology Dictionary, © 2010 Douglas Harper
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deuterium in Medicine

deuterium deu·te·ri·um (dōō-tēr'ē-əm, dyōō-)
An isotope of hydrogen with one proton and one neutron in the nucleus having an atomic weight of 2.014. Also called heavy hydrogen, hydrogen-2.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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deuterium in Science
An isotope of hydrogen whose nucleus has one proton and one neutron and whose atomic mass is 2. Deuterium is used widely as a tracer for analyzing chemical reactions, and it combines with oxygen to form heavy water. Also called heavy hydrogen. See Note at heavy water.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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