A hoodlum is a person, especially a young person, who behaves in a rough, violent, or criminal way. The word often describes someone who causes trouble in their neighborhood: breaking windows, threatening people, stealing, or starting fights. In old movies and books, you might see hoodlums hanging around street corners looking for trouble, or working as muscle for gangsters.

While hoodlum and thug are similar, hoodlum often carries a slightly old-fashioned feel and sometimes suggests someone who's more of a local troublemaker than a serious criminal. A hoodlum might steal a bicycle or intimidate other kids, while organized criminals commit more serious crimes. The word can also appear in the phrase young hoodlum, emphasizing the person's age and recklessness.