whistle
/wɪsl̩/noun
A small device that makes a loud, high sound when you blow through it, used by referees and coaches.
Example sentences
- “The referee blew the whistle to stop the game.”
- “The coach wears a whistle around her neck at practice.”
- “Fans cheered when the final whistle sounded.”
The 'final whistle' marks the end of a game. To 'blow the whistle on' wrongdoing means to report it, which gives us 'whistleblower'.