1. prisoners serving life sentences in prison
Usage: informal
2. people who spend their entire careers in one organization or profession
Usage: informal

Examples

• The prison housed several lifers who had been there for decades.
• Most of the lifers in the maximum security wing had given up hope of parole.
• The company was run by lifers who had worked there since graduation.
• Military lifers often struggle to adapt to civilian careers.
• She was surrounded by lifers who knew every detail of the organization’s history.
• The new CEO wanted to bring in fresh talent rather than promote more lifers.