Synonyms for whistle

noun

1. A shrill sound

   cry, shriek, howl, blast, piping, siren call, fire alarm, birdcall, signal, toot, blare; see also noise 1.

2. An instrument that produces a shrill sound

   fife, pipe, pipes, panpipes, tin whistle, steam whistle, mouth whistle, traffic whistle, siren, calliope.

verb

1. To produce a shrill blast

   fife, pipe, flute, trill, hiss, whiz, wheeze, shriek, howl, blare, toot, tootle; see also sound 1.

2. To call with a whistle

   signal, summon, warn, command, flag, arrest, sound a whistle.

3. To produce a tune by whistling

   warble, tootle, trill, quaver, carol, improvise.