Unrelated means having no connection or link between two or more things. When ideas, events, or people are unrelated, they exist separately without influencing each other or sharing a common cause.

If your teacher asks why you were late to school and you start talking about your favorite video game, that's an unrelated topic: it has nothing to do with the question. When scientists study whether eating carrots improves eyesight, they must be careful not to draw conclusions from unrelated factors, like whether the people in their study also happen to wear glasses.

Sometimes things appear connected but are actually unrelated. Two students might both catch a cold in the same week, but if one caught it from a sibling and the other from a classmate, those illnesses are unrelated even though they happened at the same time.

The word can also describe people who don't share family connections. Your best friend might feel like family, but technically you're unrelated because you don't share ancestors or blood ties. This meaning shows up in phrases like “two unrelated families” or “unrelated individuals.”

Understanding what's related and what's unrelated helps you think clearly, whether you're solving a math problem, writing an essay, or figuring out why something happened.