whistle (Noun) — The sound made by something moving rapidly or by steam coming out of a small aperture.
whistle (Noun) — The act of signalling (e.g., summoning) by whistling or blowing a whistle. ex. "the whistle signalled the end of the game"
whistle (Noun) — A small wind instrument that produces a whistling sound by blowing into it.
whistle (Noun) — Acoustic device that forces air or steam against an edge or into a cavity and so produces a loud shrill sound.
whistle (Noun) — An inexpensive fipple flute.
whistle (Verb) — Produce a shrill, high-pitched sound by forcing air through the mouth. ex. "I whistle when I'm happy"
whistle (Verb) — Make whistling sounds. ex. "He lay there, snoring and whistling"
whistle (Verb) — Move with, or as with, a whistling sound. ex. "The bullets whistled past him"
whistle (Verb) — Utter or express by whistling. ex. "She whistled a melody"
whistle (Verb) — Move, send, or bring as if by whistling. ex. "Her optimism whistled away these worries"
whistle (Verb) — Make a whining, ringing, or whistling sound. ex. "the kettle was whistling"
whistle (Verb) — Give a signal by whistling. ex. "She whistled for her maid"