accretion

noun

ac·​cre·​tion ə-ˈkrē-shən How to pronounce accretion (audio)
1
: the process of growth or enlargement by a gradual buildup: such as
a
: 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
: a product of accretion
especially : an extraneous addition
accretions of grime
accretionary adjective

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").

Examples of accretion in a Sentence

rocks formed by the slow accretion of limestone There was an accretion of ice on the car's windshield.
Recent Examples on the Web This later phase of accretion may have lacked another lunar-scale impact, but likely featured large incoming asteroids. Alka Tripathy-Lang, Ars Technica, 26 Jan. 2024 Travel conditions will be hazardous due to a tenth of an inch of ice accretion. Anthony Robledo, USA TODAY, 24 Jan. 2024 This is the first time that astronomers have seen an accretion disc in an extragalactic area. Laura Baisas, Popular Science, 29 Nov. 2023 Sometimes, this results in the accretion of an especially large amount of star stuff. Elizabeth Rayne, Ars Technica, 6 Oct. 2023 Rapid accretion detections like this are rare because most stars annihilated by black holes tend to be smaller and therefore not contain so much gas. Elizabeth Rayne, Ars Technica, 14 Sep. 2023 Larger black holes lead to much more complex behavior, in which the black holes grows rapidly by accretion, eventually eating the entire star. The Physics Arxiv Blog, Discover Magazine, 21 Dec. 2023 As the matter gathers, a spinning disc called an accretion disc is forming. Laura Baisas, Popular Science, 29 Nov. 2023 The difference in speed is the evidence the astronomers needed to determine that an accretion disc is present around the star. Laura Baisas, Popular Science, 29 Nov. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'accretion.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

borrowed from Latin accrētiōn-, accrētiō "increase," from accrē- (stem of accrēscere "to increase, be added") + -tiōn-, -tiō, suffix of action nouns — more at accrue

First Known Use

1615, in the meaning defined at sense 1

Time Traveler
The first known use of accretion was in 1615

Dictionary Entries Near accretion

Cite this Entry

“Accretion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/accretion. Accessed 19 Mar. 2024.

Kids Definition

accretion

noun
ac·​cre·​tion ə-ˈkrē-shən How to pronounce accretion (audio)
1
: the process of growth or enlargement
especially : increase or growth by addition on the outside
2
: a product or result of accretion

Medical Definition

accretion

noun
ac·​cre·​tion ə-ˈkrē-shən How to pronounce accretion (audio)
: the process of growth or enlargement
especially : increase by external addition or accumulation (as by adhesion of external parts or particles) compare apposition sense 1, intussusception sense 2
accretionary adjective

Legal Definition

accretion

noun
ac·​cre·​tion ə-ˈkrē-shən How to pronounce accretion (audio)
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 investedIn re Estate of Gartenlaub, 244 P. 348 (1926)

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
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

More from Merriam-Webster on accretion

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!