A Christmas custom in medieval England that involved the consumption of copious amounts of hot ale. 

The word is derived from the Old Norse "ves heill" and the Old English "wes hal," which means "be of good health" or "be of good fortune." 

The wassail-bowl grew out of the toast. It was large and originally wooden. The main ingredients of wassail included hot strong ale (usually barleywine, strong ale, or old ale), sugar, spices, and roasted apples. Today it may also be a hot mulled cider.