Collop: [link]
Collop Monday is the two days before Ash Wednesday. Slices of meat are used up, usually along with eggs for breakfast, before Lent begins.
Also known as Rose Monday, Shrove Monday, Merry Monday or Hall Monday. Hall is shortened version of "hallow", meaning "holy".
In Cornwall, England, it is called "Peasen Monday". Pea Soup is served instead.
A collop is a small piece of meat. In general, any small piece can be called a collop.