/ Dictionary / Index A accretion: Meaning and Definition of Find definitions for: ac•cre•tion Pronunciation: (u-krē'shun), [key] — n. an increase by natural growth or by gradual external addition; growth in size or extent. the result of this process. an added part; addition: The last part of the legend is a later accretion. the growing together of separate parts into a single whole. increase of property by gradual natural additions, as of land by alluvion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: accretion (Thesaurus) accrete accretion disk Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language