From Longman Dictionary of Contemporary Englishpenal servitudepenal servitudelaw when someone is punished by being kept in prison and made to do hard physical work → penal
Examples from the Corpus
penal servitude• Justice Day sentenced them both to 20 years' penal servitude.• He was on the Sûreté list and was arrested in November 1930 and sentenced to 12 years penal servitude in September 1931. 