Dictionary.com
Thesaurus.com

carnival vs. Mardi Gras

[kahr-nuh-vuhl] / ˈkɑr nə vəl /

noun

  1. a traveling amusement show, having sideshows, rides, etc.

  2. any merrymaking, revelry, or festival, as a program of sports or entertainment.

    a winter carnival.

    Synonyms:
    holiday, fete, celebration, fair
  3. the season immediately preceding Lent, often observed with merrymaking; Shrovetide.

[mahr-dee grah] / ˈmɑr di ˌgrɑ /

noun

  1. the day before Lent, celebrated in some cities, such as New Orleans and Paris, as a day of revelry and merrymaking.

  2. a pre-Lenten carnival period climaxing on the Tuesday before Ash Wednesday.