Noun

(en-noun)

The (typically undesirable) increase in concentration and or of deposition of water-borne silt in a body of water.

*{{quote-news, year=2009, date=March 20, author=Somini Sengupta, title=In Silt, Bangladesh Sees Potential Shield Against Sea Level Rise, work=New York Times citation

, passage=They are also heavily engineered upstream: a dam built upstream in neighboring India can critically stanch the flow of freshwater down here, increasingly the chances of salinity and siltation . }}

Noun

(en noun)

The act of increasing by natural growth; especially the increase of organic bodies by the internal accession of parts; organic growth.

* 1900 , , Chapter I,

There might have been a slight accretion of the moss and lichen on the shingled roof.

The act of increasing, or the matter added, by an accession of parts externally; an extraneous addition; as, an accretion of earth.

A mineral ... augments not by growth, but by accretion .

* To strip off all the subordinate parts of his as a later accretion -

Something added externally to promote growth the external growth of an item.

concretion; coherence of separate particles; as, the accretion of particles so as to form a solid mass.

(biology) A growing together of parts naturally separate, as of the fingers or toes.

(geology) The gradual increase of land by deposition of water-borne sediment.

(legal) The adhering of property to something else, by which the owner of one thing becomes possessed of a right to another; generally, gain of land by the washing up of sand or sail from the sea or a river, or by a gradual recession of the water from the usual watermark.

(legal) Gain to an heir or legatee, failure of a coheir to the same succession, or a co-legatee of the same thing, to take his share percentage.