whis·tler 
(wĭslər, hwĭs-)
(wĭslər, hwĭs-)n.
1. One that whistles: a whistler of popular tunes.
2.
a. A marmot (Marmota caligata) of the mountains of northwest North America, having a grayish coat and a shrill, whistling cry.
b. Any of various birds that produce a whistling sound.
c. A horse having a respiratory disease characterized by wheezing.
3. Physics A very-low-frequency electromagnetic wave of 1 to 30 kilohertz produced by atmospheric disturbances such as lightning and having a characteristically decreasing frequency responsible for a whistling sound in detection equipment.