An example of a whistle is what a referee blows in a soccer game.
An example of whistle is for a bird to sing out a tune.
The tea kettle whistled on the stove.
I whistled down a cab. The referee whistled that the play was dead.
The stone whistled past my head.
Wind whistled through the cracks in the windows.
Whistle a tune.
A factory whistle.
The train whistled.
Never whistle at a funeral.
She was whistling a happy tune.
A bullet whistled past.