(informal,Anglicanism) The last Sunday before the season of Advent, on which families traditionally gather in their kitchens to prepare Christmas pudding.
Etymology
From the opening words of the collect for the day in the Book of Common Prayer of 1549 and later (a translation of the Roman Missal's collect "Excita, quæsumus"): "Stir up, we beseech thee, O Lord, the wills of thy faithful people..."