Shrove Tuesday -also known as Pancake Day-is the day before Ash Wednesday and the start of Lent. The word "Shrove" stems from the Old English word "shrive", meaning "to obtain absolution for one´s sins through confession and penance". Thus Shrove Tuesday gets its name from the custom of Christians to be "shriven" before the start of Lent.
It is also called Pancake Day because it is the day traditionally for eating pancakes, as this was the way of using up the stocks of milk, butter and eggs which were forbidden during the abstinence of Lent.
Like many other festivities it has a pagan origin. It is an analogous tradition to the tradition of Carnival which developed separately in countries of Latin Europe.
On Pancake Day "pancake races" are held in villages and town all over Britain. Participants with frying pans race trough streets tossing pancakes into the air and catching them back in the pan while running.