Homonym: whistle (Signal)
A whistle is a small device that produces a high-pitched sound when air is forced through it. It is commonly made of metal, plastic, or wood and is often used in sports, signaling, or as a toy. Whistles can vary in design, with some being simple and others more complex, like those used by referees in games such as soccer or basketball.
In addition to its recreational uses, a whistle can serve practical purposes, such as alerting others in emergencies or signaling for help. Lifeguards, for example, use whistles to get attention at swimming pools or beaches. Overall, whistles are versatile tools that can be found in various settings.