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[an-tee-mat-er, an-tahy-] /ˈæn tiˌmæt ər, ˈæn taɪ-/
noun, Physics.
matter composed only of antiparticles, especially antiprotons, antineutrons, and positrons.
Origin of antimatter
First recorded in 1950-55; anti- + matter Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for antimatter
Contemporary Examples
Historical Examples
  • On the average, one atom out of every ten million in the universe was an atom of antimatter.

    Psichopath Gordon Randall Garrett
  • The distribution was unequal of course; antimatter could not exist in contact with ordinary matter.

    Psichopath Gordon Randall Garrett
British Dictionary definitions for antimatter


a form of matter composed of antiparticles, such as antihydrogen, consisting of antiprotons and positrons
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 antimatter

also anti-matter, 1953, from anti- + matter (n.).

Online Etymology Dictionary, © 2010 Douglas Harper
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antimatter in Science
A form of matter that consists of antiparticles.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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antimatter in Culture

antimatter definition

In physics, matter made of antiparticles.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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