Source : Webster's Revised Unabridged Dictionary (1913)

Cithern \Cith"ern\, n.
   See {Cittern}.

Source : WordNet®

cithern
     n : a 16th century musical instrument resembling a guitar with a
         pear-shaped soundbox and wire strings [syn: {cittern}, {cither},
          {citole}, {gittern}]