Webster's Revised Unabridged Dictionary · 1913

accretion

accretion (ak*krē"shun) , noun

[Latin accretio, from accrescere to increase. Compare Crescent, Increase, Accrue.]

1.
The act of increasing by natural growth; esp. the increase of organic bodies by the internal accession of parts; organic growth. — Arbuthnot
2.
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. — Owen
To strip off all the subordinate parts of his narrative as a later accretion. — Sir G. C. Lewis
3.
Concretion; coherence of separate particles; as, the accretion of particles so as to form a solid mass.
4.
A growing together of parts naturally separate, as of the fingers or toes. — Dana
5.
(a) (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 soil from the sea or a river, or by a gradual recession of the water from the usual watermark.
(b)
(Law) 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. — Wharton. Kent