2 litres of beer purchased takeaway from certain areas of new zealand. it may come pre-packaged in a plastic bottle or in some places you can take you own bottle and fill it yourself using bar taps for a discount (cos you don't have to pay for the bottle).Riggas were the mainstay of students in the 80s and 90s but seem to be going out of fashion due to pretension and more credit being available.
Dude, I am going down to the bottle-o for riggas. Do you want one?
Bruce: my flat rigga would be better than speights.
John: Ah c'mon, Speights is better than vb.
Bruce: My flat rigga of harringtons is better than both.