RAIN; WATER FALLING FROM THE SKY; MOISTURE CONDENSED FROM THE ATMOSPHERE THAT FALLS VISIBLY IN SEPARATE DROPS. RAIN IS LIQUID PRECIPITATION: WATER FALLING FROM THE SKY. RAINDROPS FALL TO EARTH WHEN CLOUDS BECOME SATURATED, OR FILLED, WITH WATER DROPLETS. MILLIONS OF WATER DROPLETS BUMP INTO EACH OTHER AS THEY GATHER IN A CLOUD. WHEN A SMALL WATER DROPLET BUMPS INTO A BIGGER ONE, IT CONDENSES, OR COMBINES, WITH THE LARGER ONE.