■ noun
1》 a clear, high-pitched sound made by forcing breath through a small hole between partly closed lips, or between one's teeth.
↘any similar sound.
2》 an instrument used to produce such a sound, especially for giving a signal.
3》 Brit. informal a suit. [from rhyming sl. ~ and flute .]
■ verb
1》 emit or produce a ~.
↘produce (a tune) by whistling.
↘move rapidly through the air or a narrow opening with a whistling sound.
2》 blow a ~.
3》 ( ~ for ) wish for or expect (something) in vain.
Phrases
blow the ~ on informal bring (an illicit activity) to an end by informing on the person responsible.
( as ) clean as a ~ extremely clean or clear.
~ something down the wind
1》 let go or abandon something.
2》 archaic turn a trained hawk loose by casting it off with the wind.
~ in the dark pretend to be unafraid.
Derivatives
~r noun
Origin
OE (h)wistlian (v.), (h)wistle (n.), of Gmc origin; imitative.