1. a person serving a life sentence in prison
Usage: informal
2. a person who makes a career of military service
Usage: informal; military

Examples

• The lifer had been in prison for over twenty years.
• Several lifers were transferred to the maximum security facility.
• As a lifer in the Army, he had served in multiple overseas deployments.
• The sergeant was a lifer who planned to retire after thirty years of service.
• Many lifers choose military housing over living off base.
• The prison housed both short-term inmates and lifers.