[1] : The Collaborative International Dictionary of English v.0.48

kazoo \kazoo"\, n. etymol. uncertain.
   a kind of toy or rude musical instrument, as a tube inside of
   which is a stretched string or membrane made to vibrate by
   singing or humming into the tube.
   webster 1913 suppl.

[2] : The Collaborative International Dictionary of English v.0.48

mirliton \mir"liton\, n. f.
   1. a kind of musical toy into which one sings, hums, or
      speaks, producing a coarse, reedy sound. it is also called
      a kazoo.
      webster 1913 suppl. +pjc

            trilby singing "ben bolt" into a mirliton was a
            thing to be remembered, whether one would or no
                                                  --du maurier.
      webster 1913 suppl.

   2. same as chayote2.
      pjc
see also:
kazoo chayote2 

[3] : WordNet (r) 2.0

kazoo
     n : a toy wind instrument that has a membrane that makes a sound
         when you hum into the mouthpiece

Kazoo >> K Words
Kazoo, definition of term: Kazoo
kazoo_pag1.html