From Longman Dictionary of Contemporary Englishbe under house arrestbe under house arrestto be kept as a prisoner by a government, staying inside your house rather than in a prison → house arrest
Examples from the Corpus
be under house arrest• He, he was under house arrest.• The editor of the party newspaper is under house arrest for printing a report about tanks being moved out of Tirana.• We are not in darkest prison like our brothers and sisters in the flesh, but we are under house arrest. 