Notice means to become aware of something by seeing, hearing, or sensing it. When you notice a friend's new haircut, you've paid attention and recognized something different. When you notice the smell of cookies baking, you've detected something with your senses.

Noticing requires attention. You might walk past a tree every day without really noticing its leaves turning color, until suddenly one morning the brilliant red catches your eye. Scientists notice patterns in their data. Detectives notice tiny clues others miss. The best coaches notice when their players are struggling or improving.

Notice also means a written or printed announcement, like a notice on the school bulletin board about an upcoming event, or an eviction notice a landlord gives a tenant who must move out. When you give someone advance notice, you tell them about something before it happens so they can prepare.

There's an important phrase: take notice. When something makes people take notice, it's impressive or important enough that they stop what they're doing and pay attention. A talented young musician might perform so well that professional orchestras take notice and want to work with her.