noun

A warning is a message or indication that someone gives to another person or group to alert them of a potential danger, risk, or problem.

Example

1. The weather service issued a warning for severe thunderstorms in the area, urging residents to take shelter immediately.
2. The package has a warning label that indicates it contains hazardous materials and should be handled with care.
3. The doctor gave a warning to the patient about the potential side effects of the medication and advised them to monitor their symptoms closely.