Today is Shrove Tuesday and I am repeating a post I wrote a couple of years ago.
Shrove comes from the very old, now archaic, verb 'to shrive' which means 'to impose penance' or 'to hear confession'. Traditionally Christians were shriven in preparation for Lent (which begins tomorrow).
Other, obsolete, names for the day that are in the OED include the Scottish Fastens-eve (or Fastens-een), Fastens-Tuesday, Fastgong and Fastingong.
Today is more popularly known as Pancake Day (the equivalent of Mardi Gras or Fat Tuesday). Pancakes were traditionally eaten on Pancake Day to use up all the butter and milk before Lent when such rich foods were forbidden. There are many English towns and villages which continue old traditions associated with the day. The town of Olney in Buckinghamshire holds a pancake race on Shrove Tuesday every year (you can see a video of today's race here).