Green’s Dictionary of Slang

(US) a liquor store.

1973		G.V. Higgins Digger’s Game (1981) 160: I stopped at a packy and I bought three quarts of Beefeaters.
1997–2001		Online Sl. Dict. [Internet] packie n 1. a liquor store. (‘On your way back from the beach, swing by the packie and get some beer.’).
1997–2000		Da Bomb [Internet] 21: Packy: Liquor store; package store. I’m going to the packy. Want anything?