a British colloquial term for the gherkin. Originally it was London slang corruption of the word "Olive" but when Eastern European immigrants arrived in the late 19th Century they brought a liking for pickled cucumbers which, like olives, were sold from wooden barrels and also began to be referred to as a wallies (mostly in the east-end of London).
Wally Week, the main character of Mikro-Gen's 8-bit computer game series: Automania, Pyjamarama, Everyone's A Wally, Herbert's Dummy Run, and Three Weeks in Paradise.