"Der Mummenschanz" (masculine) is derived from the Middle High German expression "schanz(e)," which meant "Würfelspiel" (game of dice) or simply "Spiel, Wagnis" (game, risk).
The etymological origin of the first part of this compound noun (Mummen), is by contrast more lost to the mists of time. On the one hand it is dated back to the Middle High German verb "mummen" or "mumman," which was used to describe a "Glücksspiel" (game of chance). On the other hand it also may be derived from the word "mumme" (mummer), which referred to a mask or a costumed person. Related modern German verbs include "vermummen" (to mask, dress up) and "einmummen" (to cover up in warm clothing).
The historic expression (die) "mumschanz" or "momschanz" (feminine) was purportedly used as a figure of speech since at least the 16th century as both a general description of a game of chance played with dice and in connection with the custom of people dressing up in masks and costumes during the Christian "Fastenzeit" (Lenten or fasting period) or "Fastnacht" (carnival, shrovetide, Shrove Tuesday, Mardi Gras) to visit homes and play dice games together.
Regardless of the precise origins of "mumme" in the German language, by the 18th century the relation to games of chance and dice had largely disappeared, so that "Mummenschanz" mostly came to mean "Maskerade" or "Maskenspiel," albeit with an often ironic tone.
Hence in modern parlance "Mummenschanz" may be deployed as a figure of speech to describe all manner of mischief-making mockery. The website of the European Parliament might, for instance, describe a comment regarding a stalled political procedure as follows: "Meines Erachtens ist es an der Zeit, diesem Mummenschanz und dieser Parodie einer demokratischen Debatte ein Ende zu setzen." (I believe it is time to call a stop to this masquerade and this caricature of democratic debate.)
The "Mummenschanz" tradition also has roots in other parts of Europe, including France and England. In this vein, a "mummer" is an Early Modern English term for a mime artist. And "Mummenschanz" can also be a mummer or a Mummers Play (also known as mumming), a seasonal folk play performed by troupes of actors known as mummers or guisers.
The Mummers Parade, held each New Year's Day in Philadelphia, is believed to be the oldest folk festival in the United States. The parade can be traced back to at least mid-17th century roots, blending elements from Swedish, Finnish, Irish, English, German and other European heritages, as well as African heritage. The parade is related to the Mummers Play tradition from England, Ireland, Scotland and Wales.
According to the Merriam-Webster dictionary, a mummer is (1) "a performer in a pantomime" (an actor) or (2) "one who goes merrymaking in disguise during festivals."