The Collaborative International Dictionary of English v.0.48:

Mick \Mick\, Mickey \Mickey\n.
   a person of Irish descent; -- an ethnic slur, offensive and
   disparaging.

   Syn: Paddy.
        [WordNet 1.5]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "Mick":
   Aussie, Boche, Canuck, Chink, Guinea, Hunk, Hunkie, Jerry, Kraut,
   Krauthead, Mickey, Paddy, dago, frog, greaseball, greaser, limey,
   wetback