Final celebration before the fasting and austerity of Lent in some Roman Catholic regions.
The most famous and probably most exuberant carnival is that of Rio de Janeiro, which is celebrated with masked balls, costumes, and parades; the best-known U.S. celebration is Mardi Gras in New Orleans. The first day of carnival season varies with local traditions, but carnival usually ends on Shrove Tuesday, the day before the start of Lent.