1. A person or thing that announces or signals the approach of another; a forerunner or herald.
Usage: Usually plural or used in singular form as 'harbinger'; often used metaphorically

Examples

• Dark clouds are harbingers of a coming storm.
• The first robin is often seen as a harbinger of spring.
• Early symptoms can be harbingers of serious illness.
• These economic indicators are harbingers of recession.
• The protesters were harbingers of the social change that would follow.
• Falling leaves are harbingers of winter.
• The discovery of new technology often harbingers a shift in industry.