Definition of "Whistle" :
noun: an inexpensive fipple flute
noun: acoustic device that forces air or steam against an edge or into a cavity and so produces a loud shrill sound
noun: a small wind instrument that produces a whistling sound by blowing into it
noun: the act of signalling (e.g., summoning) by whistling or blowing a whistle
"The whistle signalled the end of the game."
noun: the sound made by something moving rapidly or by steam coming out of a small aperture
verb: utter or express by whistling
"She whistled a melody."
verb: give a signal by whistling
"She whistled for her maid."
verb: make a whining, ringing, or whistling sound
verb: move with, or as with, a whistling sound
"The bullets whistled past him."
verb: move, send, or bring as if by whistling
"Her optimism whistled away these worries."
verb: make whistling sounds