Source : Webster's Revised Unabridged Dictionary (1913)

Whistle \Whis"tle\, v. i. [imp. & p. p. {Whistled}; p. pr. & vb.
   n. {Whistling}.] [AS. hwistlian; akin to Sw. hvissla, Dan.
   hvisle, Icel. hv[=i]sla to whisper, and E. whisper. [root]43.
   See {Whisper}.]
   1. To make a kind of musical sound, or series of sounds, by
      forcing the breath through a small orifice formed by
      contracting the lips; also, to emit a similar sound, or
      series of notes, from the mouth or beak, as birds.

            The weary plowman leaves the task of day, And,
            trudging homeward, whistles on the way. --Gay.

   2. To make a shrill sound with a wind or steam instrument,
      somewhat like that made with the lips; to blow a sharp,
      shrill tone.

   3. To sound shrill, or like a pipe; to make a sharp, shrill
      sound; as, a bullet whistles through the air.

            The wild winds whistle, and the billows roar.
                                                  --Pope.

Whistle \Whis"tle\, v. t.
   1. To form, utter, or modulate by whistling; as, to whistle a
      tune or an air.

   2. To send, signal, or call by a whistle.

            He chanced to miss his dog; we stood still till he
            had whistled him up.                  --Addison.

   {To whistle off}.
      (a) To dismiss by a whistle; -- a term in hawking. ``AS a
          long-winged hawk when he is first whistled off the
          fist, mounts aloft.'' --Burton.
      (b) Hence, in general, to turn loose; to abandon; to
          dismiss.

                I 'ld whistle her off, and let her down the wind
                To prey at fortune.               --Shak.

   Note: ``A hawk seems to have been usually sent off in this
         way, against the wind when sent in search of prey; with
         or down the wind, when turned loose, and abandoned.''
         --Nares.

Whistle \Whis"tle\, n. [AS. hwistle a pipe, flute, whistle. See
   {Whistle}, v. i.]
   1. A sharp, shrill, more or less musical sound, made by
      forcing the breath through a small orifice of the lips, or
      through or instrument which gives a similar sound; the
      sound used by a sportsman in calling his dogs; the shrill
      note of a bird; as, the sharp whistle of a boy, or of a
      boatswain's pipe; the blackbird's mellow whistle.

            Might we but hear The folded flocks, penned in their
            wattled cotes, . . . Or whistle from the lodge.
                                                  --Milton.

            The countryman could not forbear smiling, . . . and
            by that means lost his whistle.       --Spectator.

            They fear his whistle, and forsake the seas.
                                                  --Dryden.

   2. The shrill sound made by wind passing among trees or
      through crevices, or that made by bullet, or the like,
      passing rapidly through the air; the shrill noise (much
      used as a signal, etc.) made by steam or gas escaping
      through a small orifice, or impinging against the edge of
      a metallic bell or cup.

   3. An instrument in which gas or steam forced into a cavity,
      or against a thin edge, produces a sound more or less like
      that made by one who whistles through the compressed lips;
      as, a child's whistle; a boatswain's whistle; a steam
      whistle (see {Steam whistle}, under {Steam}).

            The bells she jingled, and the whistle blew. --Pope.

   4. The mouth and throat; -- so called as being the organs of
      whistling. [Colloq.]

            So was her jolly whistle well ywet.   --Chaucer.

            Let's drink the other cup to wet our whistles.
                                                  --Walton.

   {Whistle duck} (Zo["o]l.), the American golden-eye.

Source : WordNet®

whistle
     v 1: make whistling sounds; "He lay there, snoring and whistling"
     2: move with, or as with, a whistling sound; "The bullets
        whistled past him"
     3: utter or express by whistling; "She whistled a melody"
     4: move, send, or bring as if by whistling; "Her optimism
        whistled away these worries"
     5: make a whining, ringing, or whistling sound; "the kettle was
        singing"; "the bullet sang past his ear" [syn: {sing}]
     6: give a signal by whistling; "She whistled for her maid"

whistle
     n 1: the sound made by something moving rapidly or by steam
          coming out of a small aperture [syn: {whistling}]
     2: the act of signalling (e.g., summoning) by whistling or
        blowing a whistle; "the whistle signalled the end of the
        game" [syn: {whistling}]
     3: acoustic device that forces air or steam against an edge or
        into a cavity and so produces a loud shrill sound
     4: an inexpensive fipple flute [syn: {pennywhistle}, {tin
        whistle}]