1: an early English toast to someone's health
2: a hot drink that is made with wine, beer, or cider, spices, sugar, and usually baked apples and is traditionally served in a large bowl especially at Christmastime
3: riotous drinking
Going from house to house singing Christmas carols the singers would partake of a wee bit of wassail. Sounds like a good tradition to keep up with if you ask me.