[an-tee-mat-er, an-tahy-]

noun Physics.

matter composed only of antiparticles, especially antiprotons, antineutrons, and positrons.

Nearby words

  1. antimachus,
  2. antimagnetic,
  3. antimalarial,
  4. antimanic,
  5. antimasque,
  6. antimension,
  7. antimensium,
  8. antimere,
  9. antimetabole,
  10. antimetabolite

Origin of antimatter

First recorded in 1950–55; anti- + matter Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for antimatter

  • Instead, dark matter is its own antimatter, so any pair of particles that meet will destroy each other.

  • 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

Word Origin and History for antimatter



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

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for antimatter



A form of matter that consists of antiparticles.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for antimatter


In physics, matter made of antiparticles.

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