vivid
Very bright, clear, and easy to picture in your mind.
Vivid means bright, intense, and strikingly clear. A vivid sunset blazes with deep oranges and brilliant purples that seem almost impossibly bright. A vivid dream feels so real and detailed that when you wake up, you can still picture every moment as if it actually happened.
The word often describes colors or images that grab your attention: a painter might use vivid reds and yellows, or a writer might create such vivid descriptions of a forest that readers can practically smell the pine needles and hear leaves crunching underfoot. When your teacher asks you to write with vivid details, she wants you to help readers see, hear, and feel what you're describing, not just list facts.
But vivid also describes memories and experiences. A vivid memory stands out with perfect clarity even years later, every detail sharp and unmistakable. You might have vivid memories of your first day of school or a special birthday party. These memories don't fade into vague impressions. They stay bright and detailed in your mind, as clear as photographs.
The opposite of vivid would be dull, faded, or vague. Vivid things command attention and stick in your mind because of their intensity and clarity.