to make someone realize a possible danger or problem, especially one in the future
The lifeguard warned people to stay away from the rough ocean.
The meteorologist issued a weather advisory to warn residents of an approaching storm.
Parents often warn their children about the potential dangers of crossing busy streets.
Signs along the trail warned hikers about the presence of wildlife and the need for caution.
The teacher took a moment to warn the students about the challenging aspects of the upcoming exam.
