tradesman's esky
Paper bag covering a beer or other alcoholic beverage and thus allowing the drinker to enjoy said illicit beverage publically without fear of reprisal from the authorities.
Liquor store attendant: 'Tradesman's Esky mate?'
Customer: 'Cheers mate.'
*Attendant places Customer's beer in paper bag, customer opens beer and drinks on street*
Customer: 'Cheers mate.'
*Attendant places Customer's beer in paper bag, customer opens beer and drinks on street*