noun
plural whistles
[count] a small device that makes a very high and loud sound when a person blows air through it
a device through which air or steam is forced to produce a very high and loud sound
a high and loud sound made by forcing air through your lips or teeth
a sound made by blowing
blow the whistle
to tell police, reporters, etc., about something (such as a crime) that has been kept secret - usually + on
clean as a whistle
informal :very clean
wet your whistle
US informal :to have a drink
verb
whistles; whistled; whistling
to make a high sound by blowing air through your lips or teeth [no obj]
[no obj] :to produce a high and loud sound by forcing air or steam through a device
always followed by an adverb or preposition [no obj] :to move, pass, or go very fast with a high sound
whistle in the dark
or whistle past the graveyard
informal :to act or talk as if you are relaxed and not afraid when you are actually afraid or nervous