/ Dictionary / Index C chain-reacting pile: Meaning and Definition of Find definitions for: chain'-reacting pile" Pronunciation: [key] — Physics. Physics. reactor (def. 4). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. chain-react chain reaction Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language