Human: Why is the Greek god Zeus called Zeus? Assistant: 
The name Zeus is derived from the Greek word zeus, meaning thunder. In ancient Greek religion, Zeus was the chief god and the king of the gods, ruling over the other gods and the natural world. Zeus is also known as the king of the gods and the father of many gods and goddesses. Zeus was also known as the sky god, and he is often depicted as riding across the sky in a chariot drawn by swans.