Startling means surprising in a sudden, sharp way that makes you jump or gasp. When something startles you, it catches you completely off guard: a loud noise in a quiet library, a friend appearing around a corner when you thought you were alone, or discovering an unexpected fact that changes how you see something.

The word suggests a sharp jolt rather than gentle surprise. A startling discovery is shocking enough to make you stop and say, “Wait, what?” A scientist might make a startling finding that contradicts what everyone believed. A startling resemblance between two people means they look so alike it's almost eerie.

You'll often see startling describe contrasts or differences: a startling change in weather, the startling difference between two neighborhoods, or startling statistics that reveal an unexpected truth. The word carries a sense of being jolted awake, of having your attention grabbed whether you were ready or not.

When you startle someone accidentally by walking up behind them, you might apologize. But sometimes being startled leads to something good: a startling realization can help you solve a problem you'd been stuck on, or a startling piece of news might be wonderful rather than frightening.