A signal set at danger and showing a red light or other stop indication, which a train driver must not pass until it changes or until manually cleared past the signal by a dispatcher.
An indication that a potentially bad or dangerous situation could develop.
A device designed to be placed in the mouth and blown, or driven by steam or some other mechanism, to make a whistling sound.
An act of whistling.
A shrill, high-pitched sound made by whistling.
Any high-pitched sound similar to the sound made by whistling.
A suit (from whistle and flute).
The mouth and throat; so called as being the organs of whistling.
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.
To make a similar sound by forcing air through a musical instrument or a pipe etc.
To move in such a way as to create a whistling sound.
To send, signal, or call by a whistle.