A person of mild mental retardation having a mental age of from7 to12 years and generally having communication and social skills enabling some degree of academic or vocational education. The term belongs to a classification system no longer in use and is now considered offensive.痴愚者一个人智能迟缓发展，仅具有7岁到12岁的智能，一般在一定程度的学术或职业教育后能够进行交流和掌握社会技术。这个词是一个集合概念，现在不再使用，并被视为带有侮辱意味
