Rapparee-
1. a half pike. 1690, "Both horse and foot are very ill-armed, the latter having for the most part only scythes, or half pikes called Rapories."
Hist., An Irish pikeman or irregular soldier, of the kind prominent during the War of 1688-92; hence an Irish bandit, robber or freebooter.
1690, Mackenzie, writing in "Siege London-Derry- They were afterwards called Raparees, a sort of Irish Vultures that follow their Armies to prey on the spoil.
1745, Berkeley, "We have been alarmed with a report that a great body of Raparees is up in the county of Kilkenny.

Abbreviated from the OED.