Jeff in Dallas noticed that an early English pre-printed Christmas card read Merry Christmas and Happy New Year. It points to a broader history of merry. In 1800s American English, merry was common for exuberant, joyful pleasure, and it is cognate...
sugar hat n.— «The key is to find a sugar cone (also known as a “sugar hat”) which is a solid piece of white sugar that you can flame.» —“Feuerzangenbowle (Christmas Flaming Mulled Wine)” Celtnet...
cannonball Sunday n. a sparsely attended church service, especially immediately following Christmas. (source: Double-Tongued Dictionary)

