Irritate means to annoy someone or make them feel bothered and impatient. When your little brother keeps poking you while you're trying to read, he's irritating you. When a classmate taps their pencil loudly during a quiet test, that tapping sound becomes increasingly irritating.

The word suggests a persistent, nagging kind of annoyance rather than sudden anger. Someone might irritate you by asking the same question over and over, by making the same clicking sound with their mouth, or by always interrupting when you're speaking. These small bothers add up until you feel frustrated or agitated.

Irritate also has a physical meaning: to make part of your body feel uncomfortable or inflamed. Soap can irritate your eyes, making them sting and water. A scratchy sweater might irritate your skin. Smoke irritates your throat and makes you cough. When doctors talk about irritation, they often mean this physical discomfort or redness.

Whether someone is being irritating on purpose or by accident, the result is the same: you feel bothered and want it to stop. An irritant is anything that causes irritation, like dust in your eye or a person who won't stop humming the same tune.