[ uh-kree-shuhn ]
See synonyms for accretion on
  1. an increase by natural growth or by gradual external addition; growth in size or extent.

  2. the result of this process.

  1. an added part; addition: The last part of the legend is a later accretion.

  2. the growing together of separate parts into a single whole.

  3. Law. increase of property by gradual natural additions, as of land by alluvion.

Origin of accretion

First recorded in 1605–15; from Latin accrētiōn- (stem of accrētiō ), equivalent to accrēt(us), past participle of accrēscere “to grow” (ac- prefix meaning “toward” + crē- “grow” + -tus past participle suffix) + -iōn- noun suffix; see ac-, -ion

Other words from accretion

  • ac·cre·tive, ac·cre·tion·ar·y, adjective
  • non·ac·cre·tion, noun

Words Nearby accretion Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use accretion in a sentence

British Dictionary definitions for accretion


/ (əˈkriːʃən) /

  1. any gradual increase in size, as through growth or external addition

  2. something added, esp extraneously, to cause growth or an increase in size

  1. the growing together of normally separate plant or animal parts

  2. pathol

    • abnormal union or growing together of parts; adhesion

    • a mass of foreign matter collected in a cavity

  3. law an increase in the share of a beneficiary in an estate, as when a co-beneficiary fails to take his share

  4. astronomy the process in which matter under the influence of gravity is attracted to and increases the mass of a celestial body. The matter usually forms an accretion disc around the accreting object

  5. geology the process in which a continent is enlarged by the tectonic movement and deformation of the earth's crust

Origin of accretion

C17: from Latin accretiō increase, from accrēscere. See accrue

Derived forms of accretion

  • accretive or accretionary, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for accretion


[ ə-krēshən ]

  1. Geology The gradual extension of land by natural forces, as in the addition of sand to a beach by ocean currents, or the extension of a floodplain through the deposition of sediments by repeated flooding.

  2. Astronomy The accumulation of additional mass in a celestial object by the drawing together of interstellar gas and surrounding objects by gravity.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.