noun ac·cre·tion \ə-ˈkrē-shən\

Definition of accretion

  1. 1 :  the process of growth or enlargement by a gradual buildup: such asa :  increase by external addition or accumulation (as by adhesion of external parts or particles)b :  the increase of land by the action of natural forces

  2. 2 :  a product of accretion; especially :  an extraneous addition accretions of grime


play \-shə-ˌner-ē, -ˌne-rē\ adjective


play \ə-ˈkrē-tiv\ adjective

Examples of accretion in a sentence

  1. rocks formed by the slow accretion of limestone

  2. There was an accretion of ice on the car's windshield.

Did You Know?

The slow accretion of scientific knowledge over many centuries has turned into an avalanche in our time. Any accretion of ice on a grounded jet will result in takeoff delays because of the danger it poses. The land area of the Mississippi Delta increases every year from the accretion of soil washed down the Mississippi River, though the accretions happen so slowly that it's difficult to detect any increase at all. Accretion is often used in scientific writing; its usual verb form, accrue, is more often used in financial contexts ("This figure doesn't count the accrued interest on the investments").

Origin and Etymology of accretion

Latin accretion-, accretio, from accrescere — more at accrue

First Known Use: 1615

ACCRETION Defined for English Language Learners


noun ac·cre·tion \ə-ˈkrē-shən\

Definition of accretion for English Language Learners

  • : a gradual process in which layers of a material are formed as small amounts are added over time

  • : something that has grown or accumulated slowly : a product or result of gradual growth

Medical Dictionary


noun ac·cre·tion \ə-ˈkrē-shən\

Medical Definition of accretion

  1. :  the process of growth or enlargement; especially :  increase by external addition or accumulation (as by adhesion of external parts or particles)—compare apposition 1, intussusception 2


\-shə-ˌner-ē\play adjective

Law Dictionary


noun ac·cre·tion \ə-ˈkrē-shən\

Legal Definition of accretion

  1. 1 :  the process or a result of growth or enlargement: as a :  the increase or extension of the boundaries of land or the consequent acquisition of land accruing to the owner by the gradual or imperceptible action of natural forces (as by the washing up of sand or soil from the sea or a river or by a gradual recession of the water from the usual watermark); also :  accession in which the boundaries of land are enlarged by this process — compare avulsion, reliction b :  increase in the amount or extent of any kind of property or in the value of any property accretions to a trust fund resulting from the increase in value of…securities in which its corpus is invested — In re Estate of Gartenlaub, 244 P. 348 (1926) Editor's note: Accretion in value of the principal of a trust is generally not considered income. c :  enlargement of a bargaining unit by the addition of new employees

  2. 2 in the civil law of Louisiana :  the passing to an heir or conjoint legatee of the right to accept a portion of a succession resulting from the failure of a coheir or colegatee to take his or her own share

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