accretes

Accrete is a verb meaning to grow or accumulate by the gradual addition of matter; to form by accretion. The form accretes corresponds to the third-person singular present tense, as in the crust accretes material from the mantle. The noun accretion refers to the process itself or to the material that has accreted. The term is commonly used across geology, planetary science, and astronomy.

The word comes from Latin accretus, meaning joined or increased, from accrescere, to grow toward. In modern usage it retains the sense of gradual addition and attachment of new material to an existing body.

In geology and planetary science, accretion describes growth through the addition of surrounding material, such as sediment deposition or the aggregation of rock fragments at a tectonic boundary, or the buildup of planets from planetesimals in the early solar system. In plate tectonics, accretionary processes add material to continents, crustal growth, and the formation of accretionary wedges at convergent margins.

In astronomy and astrophysics, accretion refers to mass growth by gravity-driven capture of gas and dust. Material in an accretion disk or around a compact object spirals inward, often releasing energy as radiation. Accretion is central to the growth of stars, white dwarfs, neutron stars, and supermassive black holes, and it explains many observed high-energy phenomena.

Examples include the early Earth forming by accretion of planetesimals, protoplanetary disks around young stars, and accreting matter onto compact objects that emits X-rays.