From Longman Dictionary of Contemporary Englishlife sentenceˌlife ˈsentence noun [countable] SCPUNISHthe punishment of sending someone to prison for the rest of their life or for a very long time Miller is serving a life sentence for murder.
Examples from the Corpus
life sentence• John Shaw, the elected prisoners' chairman of D-wing tells John Earle, a life sentence inmate, what to expect.• The judge gave her a life sentence.• She had been served four years of a life sentence for the murder of her baby son.• Saldivar claimed she fired her gun accidentally, but she was convicted of murder and is serving a life sentence.• Her husband was serving a life sentence for murder.• Ministers will continue to review every case where a life sentence prisoner has been detained for 10 years.serving ... life sentence• He's serving a life sentence for murder. 