a person or thing that whistles.

something that makes a sound like a whistle

The windstorm was a 60-mile-an-hour whistler.

any of various birds whose wings whistle in flight, esp. the goldeneye.

thickhead ( def. 2 ) .

a large marmot, Marmota caligata, of mountainous northwestern North America, closely related to the woodchuck.

a horse afflicted with whistling.

Radio . a whistling sound heard on a radio, a type of interference caused by distant lightning.