The word SHROVE comes from the old, English word 'shrive', which means to obtain absolution for "sins" by confessing. Thereby being "shriven" before the start of 'Lent'. Pancakes were 'traditionally' eaten on this day to use up perishable goods like eggs and milk before the 40-day fasting of 'Lent'. 'Lent' being invented to give religious control over the uneducated masses during the Spring months.
Before this Christian 'tradition' was invented and tacked on to their 'Oestre/ Easter' hijacking, it is thought that the event might have originated from a pagan observation, when eating warm, round, flour & water flatbreads - symbolising the sun - was a way of celebrating the arrival of spring and the new growing season. Full moon, Spring Equinox - same as Easter (The first Sun-day after the Full Moon, after the Spring Equinox.Nature.) Things happen, change & evolve over time and we have many residual celebrations in modern calendars that are plainly and simply celebrations of our human connection to the seasons, the solar system and our place within nature.
