any of several groups with hereditary membership whose members organize and participate as costumed paraders in the annual Mardi Gras carnival

My wife, who grew up in Tampa, had told me about krewes in that city, but I never knew until I started reading Walker Percy’s The Moviegoer how krewe was spelled. According to the American Heritage Dictionary: “Krewe is only an imitation of an old-fashioned spelling of crew in its standard meaning, but the word, thanks to its association with Mardi Gras and New Orleans high society, has taken on some of the mystique of the carnival.”