Accretion a noun that means the process of gradual growth.
The Latin word for grow is accidere (ah CHEE dare ay), which, over time gradually grew into our word of the day. Accretion is often used to describe a natural process of growth that you may see in a lawn or a body of water. But it may also be used to describe something like a city’s growth. For example: the accretion of the downtown area has been interesting to watch over the years. In all my years as a city planner I’ve never seen such broad expansion.