In Antipodean slang, a fight or altercation. Generally stronger than blue, which often connotes a merely verbal stoush ("Had a blue with yer missus again, mate?"), barney usually refers to actual (or attempted, or imagined) fisticuffs ("Got into a barney down the pub and the bastards chucked me out!").

Its etymology is cloudy; one mooted antecedent is the rhyming slang "barn owl" (="row"). It is often casually assumed to be rhyming slang for "trouble" ("Barney Rubble"), which is unlikely, since the usage amply predates Federation, let alone Hanna-Barbera.

2002.06.28@14:38 call says re Barney: Also widely used in england, it seems...