To saturate something means to soak it so completely that it can't absorb any more. When you saturate a sponge with water, you've filled every tiny space inside it until water drips out. When rain saturates the ground, puddles form because the soil simply can't hold another drop.

In chemistry class, you might learn about a saturated solution: when you keep stirring sugar into water, eventually no more sugar will dissolve, no matter how hard you stir. The water has reached its saturation point.

Markets can become saturated too. If every kid in your neighborhood already has a lemonade stand, the market is saturated with lemonade stands, meaning there are too many competing for customers. News coverage can saturate the airwaves when every channel reports the same story.

The word often suggests excess or overwhelming amounts. When colors saturate a painting, they're vivid and intense. When advertisements saturate your favorite website, they fill every available space. Saturated fat in food means the fat molecules are packed as full of hydrogen atoms as chemistry allows, which helps explain why they’re solid at room temperature.