Well-known means widely recognized or familiar to many people. When something or someone is well-known, lots of people have heard about it or know who it is.

The Statue of Liberty is a well-known landmark. Shakespeare is a well-known playwright. The story of the tortoise and the hare is a well-known fable. These things are familiar to people across different places and times because they've become part of our shared culture.

Being well-known is different from being famous. A well-known scientist might be recognized by people in her field without being a household name. Your town might have a well-known bakery that everyone locally loves, even if people in the next state have never heard of it. The scale of “well-known” depends on context: well-known in your school, well-known in your city, or well-known around the world.

The term usually suggests positive recognition, though not always. A building might be well-known for its unusual architecture, whether people love it or hate it. The key is that many people know about it and would recognize it if you mentioned it.