To overlook something means to fail to notice it or to miss it, often by accident. When you overlook a spelling mistake in your essay, your eyes simply pass over it without catching the error. When a teacher overlooks a student's raised hand, she might be focused on something else and genuinely not see it. The word suggests missing something that's actually right there in front of you.

Overlook can also mean to deliberately ignore or excuse something. A coach might overlook a player's occasional lateness because she knows the player works harder than anyone else at practice. Parents might overlook small messes in your room as long as you're keeping up with homework and chores. In this sense, overlooking means choosing not to make a big deal about something.

The word has a third meaning too: a high place from which you can see a wide view below. A scenic overlook on a mountain road lets drivers pull over and enjoy the valley spread out beneath them. You might stand at an overlook in a museum and look down at the lobby below.

Notice how all three meanings involve looking at something from a position where you might miss details, whether accidentally, intentionally, or from above.