Noun. A varient of Redneck: Think Matthew McConaughey's character in "Dazed and Confused." The guy the underage kids ask to buy them cigarettes and beer, but instead of bringing back all the change, also gets a liter of Mountain Dew and a bag of Cool Ranch Doritos. Almost always seen wearing a mullet and driving an '81 Camero. Will have Zubaz pants in more remote areas.
"Hey you get change for those cigarettes?"
"No...Billy Ray got some Dew and Doritos. That snacker."
A snacker is a heroin user who tries to avoid addiction by very careful and controlled use of heroin. This term was more used in the 80's and 90's than today. A snacker is always in danger of slipping up and becoming a junkie.