A six-pack of some sort of canned beverage, typically beer. The liquor store down the road sells sixers of bud light for just $5.A: "What should a bring to the party?" B: "We don't really need anything. Maybe bring a sixer of something you like to drink."
sixer
n. a six-pack beverage container. (Usually refers to beer.) Tom showed up with three sixers and a bushel of pretzels, and we all watched the game together.