To eavesdrop means to secretly listen to a conversation you're not part of. When you eavesdrop, you're hearing things people don't know you can hear, like when you pause outside a door to catch what your parents are saying about your birthday surprise, or when you pretend to read while actually listening to your older sister's phone call.

The word comes from a time when houses had eaves, the parts of the roof that hang over the walls. Someone standing just under the eaves by a window could hear conversations inside without being seen.

Eavesdropping happens accidentally sometimes: you might overhear classmates talking about you while you're around the corner. But deliberate eavesdropping, when you're actively trying to hear private conversations, creates uncomfortable situations. Once people discover you've been listening in secret, they may feel betrayed and stop trusting you with their thoughts and feelings.

The word usually carries a negative feeling because it involves sneakiness. Even if what you overhear isn't particularly private or important, the act itself involves deception. Parents sometimes eavesdrop on their children's conversations to keep them safe, but between friends or classmates, it can damage relationships when discovered.