[ uh-kree-shuhn ]
/ əˈkri ʃən /
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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.
Law. increase of property by gradual natural additions, as of land by alluvion.
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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


ac·cre·tive, ac·cre·tion·ar·y, adjectivenon·ac·cre·tion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use accretion in a sentence

British Dictionary definitions for accretion

/ (əˈkriːʃən) /


Derived forms of accretion

accretive or accretionary, adjective

Word Origin for accretion

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

Medical definitions for accretion

[ ə-krēshən ]

Growth or increase in size by gradual external addition, fusion, or inclusion.
Increase by addition to the periphery of material of the same nature as that already present, as in the growth of crystals.accrementition
Foreign material, such as plaque or calculus, collecting on the surface of a tooth or in a cavity.
The growing together or adherence of body parts that are normally separate.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for accretion

[ ə-krēshən ]

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.
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.