What is the X in X-mas?
dish of chopped entrails, c.1400, now chiefly Scottish, but it was common throughout Middle English, perhaps from Old French agace "magpie," on analogy of the odds and ends the bird collects. The other theory [Klein, Watkins] traces it to Old English haggen "to chop" (see hack (v.1)).
a national dish of Scotland. A haggis is actually a large spherical sausage made of the liver, heart, and lungs of a sheep, all chopped and mixed with beef or mutton suet and oatmeal and seasoned with onion, cayenne pepper, and other spices. The mixture is packed into a sheep's stomach and boiled. Haggis is usually accompanied by turnips and mashed potatoes; Scotch whisky is customarily drunk with it.