Main Entry: ¹whis·tle

Pronunciation: \ˈhwi-səl, ˈwi-\

Function: noun

Usage: often attributive

Etymology: Middle English, from Old English hwistle; akin to Old Norse hvīsla to whisper

Date: before 12th century

1 a : a small wind instrument in which sound is produced by the forcible passage of breath through a slit in a short tube <a police whistle> b : a device through which air or steam is forced into a cavity or against a thin edge to produce a loud sound <a factory whistle>
2 a : a shrill clear sound produced by forcing breath out or air in through the puckered lips b : the sound produced by a whistle c : a signal given by or as if by whistling
3 : a sound that resembles a whistle; especially : a shrill clear note of or as if of a bird