
1) Carnival in Belarus 2) Carnival in Russia 3) March observance 4) Slavic holiday
Found on
https://www.crosswordclues.com/clue/maslenitsa

Maslenitsa (Ма́сленица, Масниця, Масьленіца, Maślenica, also known as Butter Week, Crepe week, or Cheesefare Week), is an Eastern Slavic religious and folk holiday. It is celebrated during the last week before Great Lent—that is, the eighth week before Eastern Orthodox Pascha (Easter). Maslenitsa corresponds to the We...
Found on
http://en.wikipedia.org/wiki/Maslenitsa
No exact match found.