A reformatory is a locked school or home, usually for young people who have broken the law. The official idea is not only to punish them, but to change their ways so they can live better when they leave — that is the “reform” in the name. In older American English this was a common word for what people now more often call a reform school, a youth detention centre, or a juvenile prison. Though actually, the word already sounds a little old-fashioned, and it has a heavy, institutional feel. It names a place, not a person, and it is more at home in history books and old news than in casual talk.

感化院。台灣舊制常叫「少年輔育院」，現在多稱「矯正學校」；日常仍聽得懂「感化院」。