A group of people, typically peers, who partake in and elicit immoral, criminal, and/or dangerous behavior and attitudes. Mary had been a model student all her life, but when she got to senior year of high school, she started hanging out with the wrong crowd, and her grades suffered as a result. Because there is no sort of network in place to keep young people active and engaged in this part of the city, it's all too easy for them to fall in with the wrong crowd.