A Well Drink is a simple drink that is very easy to make. It is just a fruit
juice or soda that is mixed in a glass with a base LIQUOR.
Some examples of a LIQUOR: vodka, rum, dark rum, Gin, whiskey, or tequila:
white, gold, and anejo.
Types of well drinks: Screwdriver, Rum and coke, Greyhound, Cape Codder, etc.
A Well Drink, in a bar or club, is usually the cheapest brand of liquor mixed
with canned fruit juice or bottled soda.
A Well Drink "IS NOT" a fruit juice or soda that is mixed with a LIQUEUR.
A LIQUEUR is a base liquor in which fruit and sweeteners have been added.
Examples: Curacao, Kahlua, Southern Comfort etc.
A Margarita is not a well drink.
Maybe someone knows where the term "well drink" comes from.
Hope this helps.