Mardi Gras UK /ˈmɑːdi ɡɹɑː/US /ˈmɑɹdi ɡɹɑ/ noun1 •The day when traditionally all fat and meat in the house were finished up, before Christians were banned from eating them during Lent, which commenced the following day on Ash Wednesday.Mardi-gras was ushered in with various ceremonies, offering a strange mixture of devotion and profaneness. — 1839