Rosenmontag

Etymology
From West Central German dialects. Analysable as, but originally probably equivalent to standard German. The forms and  merge in some dialects, e.g. in the Palatinate. Dialects that do maintain a distinction, however, generally use the word for “rose” (compare 🇨🇬), meaning that the reinterpretation must be rather old.

Noun

 * 1) Rosenmontag, Collop Monday, Rose Monday, Merry Monday, Hall Monday the Monday before Ash Wednesday, highlight of the German carnival season