/ Dictionary / Index D delta particle: Meaning and Definition of Find definitions for: del'ta par"ticle Pronunciation: [key] — Physics. Physics. any of a family of baryon resonances having strangeness 0, isotopic spin , and either a single or double positive electric charge, a single negative charge, or no charge. Symbol: &Dgr; Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. delta iron delta ray 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