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noun Physics.
  1. atomic mass unit.

Origin of dalton

First recorded in 1935–40; named after J. Dalton


  1. John,1766–1844, English chemist and physicist.
  2. Robert,1867–92, U.S. outlaw in the West.
  3. a city in NW Georgia.
  4. a male given name.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

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British Dictionary definitions for dalton


  1. another name for atomic mass unit

Word Origin

C20: named after John Dalton


  1. John. 1766–1844, English chemist and physicist, who formulated the modern form of the atomic theory and the law of partial pressures for gases. He also gave the first accurate description of colour blindness, from which he suffered
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

Word Origin and History for dalton


in reference to a system of school education designed by Helen Parkhurst, 1920, from Dalton, Massachusetts, U.S., where it was first adopted. For Daltonism see color blindness.

Online Etymology Dictionary, © 2010 Douglas Harper

dalton in Medicine


  1. atomic mass unit

dalton in Science


  1. See atomic mass unit.


  1. British chemist whose pioneering work on the properties of the atmosphere and gases led him to formulate the atomic theory. Dalton's theory stipulates that all matter is made up of combinations of atoms, the atoms of each element being identical. These atoms can be neither created nor destroyed, but chemical reactions take place through their rearrangement.
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