reform school
From Longman Dictionary of Contemporary Englishreform schoolreˈform school noun [countable] American Englishx-ref a special school where young people who have broken the law are sent If you’re not careful, you’ll end up in reform school.Examples from the Corpusreform school• Some one had told him that it must be a reform school and so he sat all day in tears.• Later, after being expelled from school, he was sent to reform school.