From Longman Dictionary of Contemporary Englishpreventive detentionpreˌventive deˈtention noun [uncountable] British English lawSCJ a system in which people who are guilty of many crimes are kept in prison for a long time
Examples from the Corpus
preventive detention• Her order of preventive detention caused consternation among lawyers over a possible breach of civil liberties.• Apart from the clearly implied step toward preventive detention, it was almost impossible not to detect an underlying racism. 