An _______ is a sudden shaking or trembling of the earth.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a term that describes a sudden shaking or trembling of the earth.

2. **Identifying the Phenomenon**: When we experience a sudden shaking of the ground, it indicates a natural occurrence that affects the earth's surface.

3. **Recalling the Term**: The term commonly used to describe this phenomenon is "Earthquake."

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