accretion

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Growth or increase in size by gradual external addition, fusion, or inclusion.
• noun Something contributing to such growth or increase.
• noun Biology The growing together or adherence of parts that are normally separate.
• noun Slow addition to land by deposition of water-borne sediment.
• noun An increase of land along the shores of a body of water, as by alluvial deposit.
• noun Astronomy An increase in the mass of a celestial object by its gravitational capture of surrounding interstellar material.

from The Century Dictionary.

• noun In forestry, increase in diameter or height: distinguished from increment, increase in volume.
• noun In petrol., a term proposed by Johnston-Lavis for a mass formed in solution by deposition about a nucleus, as in oölite, or upon the walls of a cavity.
• noun The act of accreting or accrescing; a growing to; an increase by natural growth; an addition; specifically, an increase by an accession of parts externally.
• noun In pathology, the growing together of parts normally separate, as the fingers or toes.
• noun The thing added; an extraneous addition; an accession: commonly used in the plural, and restricted to accessions made slowly and gradually by some external force.
• noun In law: The increase or growth of property by external accessions, as by alluvium naturally added to land situated on the bank of a river, or on the seashore.
• noun In Scots law, the completion of an originally defective or imperfect right by some subsequent act on the part of the person from whom the right was derived.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of increasing by natural growth; esp. the increase of organic bodies by the internal accession of parts; organic growth.
• noun The act of increasing, or the matter added, by an accession of parts externally; an extraneous addition.
• noun Concretion; coherence of separate particles.
• noun A growing together of parts naturally separate, as of the fingers or toes.
• noun 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 soil from the sea or a river, or by a gradual recession of the water from the usual watermark.
• noun Gain to an heir or legatee, by failure of a coheir to the same succession, or a co-legatee of the same thing, to take his share.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The act of increasing by natural growth; especially the increase of organic bodies by the internal accession of parts; organic growth.
• noun The act of increasing, or the matter added, by an accession of parts externally; an extraneous addition; as, an accretion of earth.
• noun Something added externally to promote growth the external growth of an item.
• noun concretion; coherence of separate particles; as, the accretion of particles so as to form a solid mass.
• noun biology A growing together of parts naturally separate, as of the fingers or toes.
• noun geology The gradual increase of land by deposition of water-borne sediment.
• noun law 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.
• noun law 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.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun something contributing to growth or increase
• noun (biology) growth by addition as by the adhesion of parts or particles
• noun (geology) an increase in land resulting from alluvial deposits or waterborne sediment
• noun (astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases
• noun (law) an increase in a beneficiary's share in an estate (as when a co-beneficiary dies or fails to meet some condition or rejects the inheritance)
• noun an increase by natural growth or addition