snakebite
From The Oxford Companion to Beer
is a mixture of lager and alcoholic cider that is sometimes euphemistically referred to as a “beer cocktail.” Technically, as a mix of drinks, it is a cocktail, but beyond that technicality it has little in common with what we generally think of as cocktails.
Snakebite is popular in Britain and had its heyday in the 1980s, when it was a popular drink among students and youth subcultures such as “Goths” and “punks.” Often a shot of blackcurrant cordial would be added, to create “snakebite and black,” “Diesel,” or “Purple Nasty.”
These names give some clue as to snakebite’s appeal among young, budget-conscious drinkers who are often more interested in the intoxicating qualities of alcohol than its flavor: Snakebite is cloudy, looks and tastes unappetizing, and is commonly believed to get you drunk more quickly than lager or cider separately.
For this reason, there is an urban myth that snakebite is illegal in Britain; this is not true. Pubs are not allowed to serve half pints of snakebite, because this would mean serving incomplete measures of both cider and lager (draught products may only legally be sold in third, half, or full pint measures) but they are perfectly at liberty to serve a half of cider and a half of lager in a pint glass. However, some pubs reserve the right to refuse to do so thanks to the drink’s reputation and its tendency to attract undesirable drinkers, particularly in a climate of concern over binge drinking.
This definition is from The Oxford Companion to Beer, edited by Garrett Oliver. © Oxford University Press 2012.