Hurricane: this word is used especially of storms in the western Atlantic. It is a violent storm with very strong winds. In other parts of the world, especially Asia, it is called a typhoon.
Earthquake: a sudden violent movement of the ground causing damage.
Tidal wave: a very large ocean wave that is caused by a storm or earthquake, and which destroys things when it reaches land.
Volcanic eruption: a volcano is a mountain with a hole in the top, and when it erupts, hot gases and lava are forced out into the air and onto the surrounding land.
Drought: a long period with no rain. Crops die, and people may starve to death.