/ Dictionary / Index C cascade particle: Meaning and Definition of Find definitions for: cascade' par"ticle Pronunciation: [key] — Physics. Physics. the least massive member of the xi particle family. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cascade Cascade Range Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language