blow the whistle, to expose the existence of mischief or wrongdoing: The agent was taking bribes until someone finally blew the whistle.
    blow the whistle on,
    1. to bring a stop to; halt: Congress has blown the whistle on all unnecessary expenditures for the program.
    2. to expose (wrongdoing or wrongdoers): to blow the whistle on corruption in high places.
    wet one's whistle, Informal. to take a drink.
    whistle in the dark, to attempt to summon up one's courage or optimism in a difficult situation: He says his business will improve next year, but he's probably just whistling in the dark.

Origin of whistle

before 950; (v.) Middle English whistlen, Old English hwistlian; akin to Old Norse hvīsla to whistle, hviskra to whisper; see whine; (noun) Middle English; Old English hwistle instrument, akin to the v.
Related formswhis·tle·a·ble, adjectivein·ter·whis·tle, verb (used with object), in·ter·whis·tled, in·ter·whis·tling.un·whis·tled, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for blow the whistle on



to produce (shrill or flutelike musical sounds), as by passing breath through a narrow constriction most easily formed by the pursed lipshe whistled a melody
(tr) to signal, summon, or command by whistling or blowing a whistlethe referee whistled the end of the game
(of a kettle, train, etc) to produce (a shrill sound) caused by the emission of steam through a small aperture
(intr) to move with a whistling sound caused by rapid passage through the air
(of animals, esp birds) to emit (a shrill sound) resembling human whistling
whistle in the dark to try to keep up one's confidence in spite of fear


a device for making a shrill high-pitched sound by means of air or steam under pressure
a shrill sound effected by whistling
a whistling sound, as of a bird, bullet, the wind, etc
a signal, warning, command, etc, transmitted by or as if by a whistle
the act of whistling
music any pipe that is blown down its end and produces sounds on the principle of a flue pipe, usually having as a mouthpiece a fipple cut in the side
wet one's whistle informal to take an alcoholic drink
blow the whistle (usually foll by on) informal
  1. to inform (on)
  2. to bring a stop (to)

Word Origin for whistle

Old English hwistlian; related to Old Norse hvīsla
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for blow the whistle on



"tubular musical instrument," Old English hwistle (see whistle (v.)). To wet one's whistle "take a drink" (late 14c.) originally may have referred to pipes, or be an allusion to the throat as a sort of pipe. Phrase clean as a whistle is recorded from 1878. Railroad whistle stop (at which trains stop only if the engineer hears a signal from the station) is recorded from 1934.



Old English hwistlian, from Proto-Germanic *khwis-, of imitative origin. Used also in Middle English of the hissing of serpents. Related: Whistled; whistling. To whistle for (with small prospect of getting) is probably from nautical whistling for a wind. To whistle "Dixie" is from 1940.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with blow the whistle on

blow the whistle on


Expose corruption or other wrongdoing, as in The President's speech blew the whistle on the opposition's leaking information. [Colloquial; 1930s]


Put a stop to, as in The registry decided to blow the whistle on new vanity plates. The term originally alluded to ending an activity (such as factory work) with the blast of a whistle. [Late 1800s]


In addition to the idioms beginning with whistle

  • whistle Dixie
  • whistle for
  • whistle in the dark

also see:

  • blow the whistle on
  • clean as a whistle
  • slick as a whistle
  • wet one's whistle
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.