Source : Webster's Revised Unabridged Dictionary (1913)

Zither \Zith"er\, n. [G. zither. See {Cittern}.] (Mus.)
   An instrument of music used in Austria and Germany. It has
   from thirty to forty wires strung across a shallow
   sounding-board, which lies horizontally on a table before the
   performer, who uses both hands in playing on it.

   Note: [Not to be confounded with the old lute-shaped cittern,
         or cithern.]

Source : WordNet®

zither
     n : a musical stringed instrument with strings stretch over a
         flat sounding box; it is laid flat and played with a
         plectrum and with fingers [syn: {cither}, {zithern}]