Green’s Dictionary of Slang

1. a particularly good party.

1989		P. Munro Sl. U.
1999		Eble Campus Sl. Nov. 10: rager – large, out-of-control party.

2. (also rage) a person, or animal, known for wild behaviour.

1890		‘Rolf Boldrewood’ Colonial Reformer II 107: A livelier lot of ‘ragers’ I haven’t seen for many a day.
1901		‘Rolf Boldrewood’ In Bad Company 275: Father’s going on like an old ‘rager’ bullock.
1968		(con. 1930s) J. Healy Death of an Irish Town 20: They were, in the current slang of the town, ‘the buff shams’, ‘rager coves’.
1973		(con. mid-1960s) J. Patrick Glasgow Gang Observed 131: He’s a right rage, aw right.
1989		P. Munro Sl. U.
2003		McGill Reed Dict. of N.Z. Sl.