1. people who give warnings or alerts about danger or problems

Examples

• The weather warners issued a tornado alert for the county.
• Environmental warners have been predicting this crisis for decades.
• The warners at the construction site directed traffic away from the hazard.
• Public health warners advised residents to boil their water.
• The warners posted signs about the dangerous currents at the beach.
• Fire warners evacuated the building when smoke was detected.