whis·tle / ˈ(h)wisəl/ • n. a clear, high-pitched sound made by forcing breath through a small hole between partly closed lips, or between one's teeth. ∎  a similar sound, esp. one made by a bird, machine, or the wind. ∎  an instrument used to produce such a sound, esp. for giving a signal.• v. 1. [intr.] emit a clear, high-pitched sound by forcing breath through a small hole between one's lips or teeth: the audience cheered and whistled | [as n.] (whistling) I awoke to their cheerful whistling | [as adj.] (whistling) a whistling noise. ∎  express surprise, admiration, or derision by making such a sound: Bob whistled. “You look beautiful!” he said. ∎  [tr.] produce (a tune) in such a way. ∎  (esp. of a bird or machine) produce a similar sound: the kettle began to whistle. ∎  [intr.] produce such a sound by moving rapidly through the air or a narrow opening: the wind was whistling down the chimney. ∎  blow an instrument that makes such a sound, esp. as a signal: the referee did not whistle for a foul. ∎  [tr.] (whistle someone/something up) summon something or someone by making such a sound.2. (whistle for) wish for or expect (something) in vain: you can go home and whistle for your wages.PHRASES: blow the whistle on inf. bring an illicit activity to an end by informing on the person responsible. (as) clean as a whistle extremely clean or clear. ∎ inf. free of incriminating evidence: the cops raided the warehouse but the place was clean as a whistle.whistle something down the wind let something go; abandon something. ∎  turn a trained hawk loose by casting it off with the wind.whistle in the dark pretend to be unafraid.whistle in the wind try unsuccessfully to influence something that cannot be changed.