1. Plural of flatliner; people or patients whose heart rate or vital signs have stopped, showing a flat line on a monitor.
Usage: medical; informal
2. Plural of flatliner; things or situations that show no growth, progress, or change; stagnant or static conditions.
Usage: informal; figurative

Examples

• The emergency room was filled with flatliners who needed immediate resuscitation.
• The company's sales have become flatliners over the past two quarters.
• Several flatliners were revived by the medical team using CPR and defibrillation.
• The economy showed flatliners in consumer spending last month.
• Doctors worked quickly to stabilize the flatliners in the ICU.