Accretion (astrophysics)


(1)   (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)
(2)   An increase by natural growth or addition
(3)   (geology) an increase in land resulting from alluvial deposits or waterborne sediment
(4)   (biology) growth by addition as by the adhesion of parts or particles
(5)   (astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases
(6)   Something contributing to growth or increase
"He scraped away the accretions of paint"
"The central city surrounded by recent accretions"


Latin accretio, from . 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.
  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 grown, but by accretion.
    • To strip off all the subordinate parts of his as a later accretion - George Cornewall 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.
  5. 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.
  6. 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.