/ Dictionary / Index J Jpn.: Meaning and Definition of Find definitions for: Jpn. Pronunciation: [key] Japan. Japanese. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. J particle J/psi particle Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language