A whistle is a high-pitched sound made by forcing air through your mouth or using an object.
When someone blows their whistle, it's often to get attention - like a referee on the sports field to stop play. You might also hear a train whistle in the distance, or a security guard blowing their whistle to alert others of something suspicious. Even children use whistles to summon friends or parents. Whistles can be loud and sharp, so they tend to cut through noise and get people's attention right away.
A device designed to be placed in the mouth and blown, or driven by steam or some other mechanism, to make a whistling sound.
To make a shrill, high-pitched sound by forcing air through the mouth. To produce a whistling sound, restrictions to the flow of air are created using the teeth, tongue and lips.
Example: Never whistle at a funeral.
