To indicate means to point out, show, or signal something. When dark clouds indicate rain, they're giving you a sign that a storm is coming. When a thermometer indicates 98.6 degrees, it's showing your body temperature. When you indicate which book you want at the library, you're pointing it out to the librarian.

The word often suggests indirect showing rather than stating something directly. A teacher might indicate disappointment by sighing and shaking her head, without saying a word. Your dog indicates excitement about a walk by wagging his tail and running to the door. Test results might indicate that you've mastered multiplication, meaning they show clear evidence of your understanding.

In everyday use, indicate sounds more formal than simple words like “show” or “point out,” so you'll often hear it in scientific contexts, official announcements, or careful explanations. A scientist might say her research indicates a connection between two things, meaning the evidence points toward that conclusion without absolutely proving it.

On roads, turn signals are called indicators because they indicate which direction a car plans to turn.