antimatter[an′ti mat′ər; -tī-, -tē-]
antimatter definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a form of matter in which the electrical charge or other property of each constituent particle is the reverse of that in the usual matter of our universe: an atom of antimatter has a nucleus of antiprotons and antineutrons surrounded by positrons
antimatter definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A hypothetical form of matter that is identical to physical matter except that its atoms are composed of antielectrons, antiprotons, and antineutrons.
antimatter - Cultural Definition
antimatter - Science Definition
A form of matter that consists of antiparticles.