The word shrove is a past tense of the English verb “shrive,” which means to obtain absolution (forgiveness) for one’s sins by confessing and doing penance. Shrove Tuesday gets its name from the shriving (confession) that Anglo-Saxon Christians were expected to receive immediately before Lent.
The reason that pancakes are associated with the day preceding Lent is that the 40 days of Lent form a period of liturgical fasting, during which only the plainest foodstuffs can be eaten. Therefore, rich ingredients such as eggs, milk, sugar and flour are disposed of immediately prior to the commencement of the fast. Pancakes were therefore the perfect way of using up these perishable goods, besides providing a minor celebratory feast prior to the fast itself.