a suffix used in the names of subatomic particles (gluon; meson; neutron), quanta (graviton), and other minimal entities or components (cistron; codon; magneton; photon).

Nearby words

  1. -ole,
  2. -ologist,
  3. -ology,
  4. -oma,
  5. -ome,
  6. -one,
  7. -onic,
  8. -onium,
  9. -ont,
  10. -onym

Origin of -on

probably extracted from ion; cf. proton



a suffix used in the naming of inert gaseous elements: neon.

Origin of -on

Greek -on, neuter of -os adj. ending

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for -on


suffix forming nouns

indicating a chemical substanceinterferon; parathion
(in physics) indicating an elementary particle or quantumelectron; photon
(in chemistry) indicating an inert gasneon; radon
(in biochemistry) a molecular unitcodon; operon

Word Origin for -on

from ion

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 -on


subatomic particle suffix, from ion.

Online Etymology Dictionary, © 2010 Douglas Harper