A pseudo-alcoholic drink available in Britain and maybe elsewhere. Usually it's a 50:50 combination of beer (either bitter or lager) and lemonade. Popular with those unable or unwilling to handle their drink.

My favorite version is 50-50 beer (something lagerish) and ginger ale. And contrary to iain's opinion, I do not believe this quaff is for someone "unable or unwilling to handle their drink." This is a very refreshing drink on a hot day whether or not it follows exertion of any sort.

The most common form is the combination of a lager (Mexican beers are excellent for this) and some lemon soda.
The ginger ale - lager combo is traditionally known as a shandygaff.