a (usually long) tuneful sound made by forcing air or stream through a small opening (e.g. the mouth, a bird's beak) or made by the wind; a simple instrument making a similar sound as used by a referee in games and sports
make sharp, shrill sound
Cases of word usage
1) a short, quick look, often secret or cautious; a weak, high sound made by a mouse, whistle etc (peep)
