Uncouth means lacking good manners, refinement, or social grace. An uncouth person might talk with their mouth full, burp loudly without saying “excuse me,” or interrupt others constantly. They act in ways that make people around them uncomfortable or embarrassed.

The word suggests a pattern of behavior, not occasional rudeness. Someone who forgets to say “please” once isn't uncouth, but someone who consistently ignores basic courtesy might be. An uncouth dinner guest might reach across the table to grab food instead of asking someone to pass it, or make rude comments about the meal while the host is listening.

While everyone makes social mistakes sometimes, being truly uncouth means regularly acting without consideration for basic social expectations or other people's feelings.