/ Dictionary / Index A antinucleon: Meaning and Definition of Find definitions for: an•ti•nu•cle•on Pronunciation: (an"tē-n'klē-on", -ny'-, an"tī-), [key] — n. Physics. an antiproton or an antineutron. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. antinuclear antinuke Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language