/ Dictionary / Index A atomism: Meaning and Definition of Find definitions for: at•om•ism Pronunciation: (at'u-miz"um), [key] — n. Also calledthe theory that minute, discrete, finite, and indivisible elements are the ultimate constituents of all matter. a method or theory that reduces all psychological phenomena to simple elements. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: atomism (Thesaurus) atomic weight atomize Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language