What is the process called when cloud droplets merge together to fall as precipitation?

The process through which cloud droplets merge together to fall as precipitation is known as coalescence. During coalescence, small water droplets within a cloud collide and combine with larger droplets, eventually becoming heavy enough to overcome air resistance and fall to the ground as rain. This phenomenon is essential in the formation of precipitation, as it allows for the growth of droplets from tiny sizes to larger ones that can precipitate.

Cohesion refers to the attraction between molecules within a substance, which helps maintain droplet formation but does not directly lead to precipitation. Condensation is the process where water vapor changes into liquid water, forming droplets in the atmosphere but not specifically describing their merging. Evaporation is the process of liquid water transforming into vapor, which also does not pertain to the merging of droplets to form precipitation. Therefore, coalescence is the correct term to describe the merging process of cloud droplets that results in precipitation.