The Collaborative International Dictionary of English v.0.48:

Spalpeen \Spal"peen\, n. [Ir. spailpin, fr. spailp a beau,
   pride, self-conceit.]
   A scamp; an Irish term for a good-for-nothing fellow; --
   often used in good-humored contempt or ridicule. [Colloq.]
   [1913 Webster]