Thunderhead (noun)

A large, dark, and often turbulent cloud that is associated with thunderstorms, typically characterized by a flat top and a bulging middle.

Origin:

The word thunderhead comes from the combination of the words "thunder" and "head" which describe the cloud formation that is the source of thunderstorms.

Examples:

1. The thunderhead was moving towards the city, bringing with it strong winds and heavy rain.
2. Thunderheads are typically made of cumulonimbus clouds, which are tall and can reach heights of over 20,000 feet.
3. Thunderheads can form in a matter of minutes and can produce lightning and thunder.
4. The thunderhead in the sky was a sign of an approaching storm.
5. Thunderheads are often accompanied by strong winds, heavy rain, and sometimes tornadoes or hail.