The Collaborative International Dictionary of English v.0.48:

Punchinello \Pun`chi*nel"lo\, n. [It. pulcinella, probably
   originally a word of endearment, dim. of pulcina, pulcino, a
   chicken, from L. pullicenus, pullus. See Pullet.]
   A punch; a buffoon; originally, in a puppet show, a character
   represented as fat, short, and humpbacked. --Spectator.
   [1913 Webster]