accretion

/əˈkriːʃən/
noun
  1. A gradual increase or addition of something over time, especially by layers or small amounts building up.
    • Over millions of years, the accretion of sediment formed new layers of rock.
    • The accretion of dust on the old bookshelf made it look ancient.
    • The company's growth was due to the steady accretion of small clients.
  2. Something that has been added or built up gradually; an accumulation.
    • The coral reef is an accretion of tiny marine organisms.
    • His knowledge was an accretion of facts from years of reading.
    • The old city walls had many accretions of graffiti and moss.
  3. In astronomy, the process by which dust and gas in space come together under gravity to form larger bodies like stars and planets.
    • Scientists study accretion to understand how solar systems develop.
    • Planets form through the accretion of dust and gas in a protoplanetary disk.
    • The accretion of matter onto a black hole releases huge amounts of energy.
What does "accretion" mean? | whatsthatwordmean | whatsthatwordmean