There are lots of possible answers,
tributaries
Streams join together to become rivers. Then the water from the rivers and streams will eventually run into the ocean or a lake.
the allegheny and monongahela rivers come together and form the Ohio river in Pittsburgh....
Ido
watershed
The energy for running water in streams come from from heaven.
The type of rays that come together are called convergent rays.
Continental drift is the theory that explains how the Earth's continents have moved over time due to the process of plate tectonics. About 300 million years ago, all the continents were part of a supercontinent called Pangaea. Over time, the movement of tectonic plates has separated and repositioned the continents to their current locations.
The arteriovenous capillary bed is formed when very small arteries come together with very small veins. These very small veins are called venules and the very small arteries are called arterioles. This is where gas exchange occurs between the circulatory system and the cells.
clumps of bacteria come together and impurities come together to form a cluster called as floc and the chemicals that are used for this purpose are called floceulants.
a place where two rivers or streams join to become one : a situation in which two things come together or happen at the same time
It is called a compound.