Mardi Gras (n.)youdaoicibaDictYouDict[Mardi Gras 词源字典]
1690s, from French, literally "fat Tuesday," from mardi "Tuesday" (12c., from Latin Martis diem "day of the planet Mars;" see Tuesday) + gras "fat," from Latin crassus, "thick." Day of eating and merrymaking before the fasting season of Lent.[Mardi Gras etymology, Mardi Gras origin, 英语词源]