Accreted

Accreted is the past participle of accrete, meaning formed or grown by gradual accumulation of matter or layers. In general usage, something accreted has been added to something larger over time through the gradual addition of material or components.

In geology, accretion describes the process by which crustal blocks or terranes formed elsewhere are sutured to a continental plate. Accreted terranes are often distinct in age, composition, and structure from the host crust. The western margins of North America contain many accreted terranes, reflecting a long history of plate tectonics.

In astronomy and planetary science, accretion is the growth of a body by gravitational attraction and accumulation of gas, dust, and other material. An accreted region or disk gains material from its surroundings, such as an accretion disk around a young star or a compact object. Galaxies grow by accreting stars and gas from smaller systems, leaving observable stellar streams and chemical signatures.

In broader use, accreted describes developments built up gradually, rather than replaced wholesale. The term is widely used to describe processes in astronomy, geology, and planetary science, where growth occurs through addition of material over time.

Etymology: from Latin accretus, the past participle of accrescere “to grow toward,” from ad- “toward” + crescere “to grow.”