antiproton

[an-tee-proh-ton, an-tahy-]
noun Physics.
  1. an elementary particle having negative charge equal in magnitude to that of the electron and having the same mass and spin as a proton; the antiparticle of the proton.

Origin of antiproton

First recorded in 1935–40; anti- + proton
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for antiproton

antiproton

noun
  1. the antiparticle of the proton; a particle having the same mass as the proton but an equal and opposite charge
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

antiproton in Science

antiproton

[ăn′tē-prōtŏn′, ăn′tī-]
  1. The antiparticle that corresponds to the proton.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.