- Growth or increase in size by gradual external addition, fusion, or inclusion.
- Something contributing to such growth or increase: "the accretions of paint that had buried the door's details like snow" (Christopher Andreae).
- Biology. The growing together or adherence of parts that are normally separate.
- Geology.
- Slow addition to land by deposition of water-borne sediment.
- An increase of land along the shores of a body of water, as by alluvial deposit.
- Astronomy. An increase in the mass of a celestial object by the collection of surrounding interstellar gases and objects by gravity.
[Latin accrētiō, accrētiōn-, from accrētus, past participle of accrēscere, to grow. See accrue.]
accretionary ac·cre'tion·ar'y (-shə-nĕr'ē) or ac·cre'tive adj.





