1. advance notice or warning given before something happens
Usage: often considered redundant since ‘warning’ already implies advance notice

Examples

• The weather service issued a prewarning about the approaching storm.
• We received a prewarning that the system would be down for maintenance.
• The company gave employees a prewarning about potential layoffs.
• Without any prewarning, the meeting was suddenly canceled.
• The prewarning allowed residents to evacuate safely.
• She appreciated the prewarning about the difficult exam questions.