Plough Monday
noun
The first Monday after Epiphany, formerly marked by popular festivals or observances in some regions.The first Monday after the twelve days of Christmas (Twelfth Night) is Plough Monday, a day when ploughmen traditionally blackened their faces and wore white shirts....
- Plow Monday was a historical observance whose first heyday was in the nineteenth century.
Origin
From the custom of dragging a plough through the streets to mark the beginning of the ploughing season.