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