The term 'Flood Cause' can be solved by two crossword solutions: RAIN (4 letters) and RAINSTORM (9 letters). RAIN is a form of precipitation that falls from the sky in the form of liquid water droplets. It is a major component of the water cycle and is responsible for replenishing the Earth's water supply. A RAINSTORM is a more intense form of RAIN, usually accompanied by strong winds and thunder. It is often associated with flooding due to the large amount of water it can bring in a short period of time.