Select the word that is closest in meaning to “dreary”.

The correct answer is Dull.

Detailed Explanation:
The word "dreary" is an adjective used to describe something that is gloomy, bleak, depressing, or lacking brightness, cheerfulness, and excitement.

To find the word closest in meaning, let's analyze each of the given options:
1. Vibrant: Means full of energy, brightness, and life. This is the opposite (antonym) of dreary.
2. Radiant: Means shining brightly, glowing, or expressing vivid happiness. This is also an opposite (antonym) of dreary.
3. Dull: Means lacking interest, excitement, or brightness; lifeless, gloomy, or boring. This directly aligns with the meaning of dreary.
4. Cheerful: Means noticeably happy and optimistic. This is an opposite (antonym) of dreary.

Therefore, among all the options, Dull is the word closest in meaning to "dreary".