Noun
a person appointed master of revels at a Christmas celebration
Source: WordNetFor the start of the Roman Saturnalia, on December 17 authorities chose an enemy of the Roman people to represent the Lord of Misrule in each community. Source: Internet
He still continued to be regarded as Christmas's presiding spirit, although his occasional earlier associations with the Lord of Misrule died out with the disappearance of the Lord of Misrule himself. Source: Internet