(Italian dolcimello), according to Bishop (Musical Dictionary, p. 45), is “a triangular chest strung with wires, which are struck with a little rod held in each hand;” but the word “symphonia,” translated dulcimer in Daniel iii. 5, was a species of bagpipe. Fürst deduces it from the Hebrew smpn (a pipe).
“The sound of cornet, flute, harp, sackbut psaltery, [symphony] or dulcimer, and all kinds of music.” —Dan. iii. 5.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Dulcimer from Infoplease: