Although most frequently used to indicate meaningless words that are supposed to have magickal effects but in reality have no power at all, the origin may be a corruption of the Mandingo language where
ma-ma-gyo-mbo means means a magician who makes the troubled spirits of ancestors depart. Another version says it’s a corruption of the Mandingo words
Mama Dyumbo. Its first use was in 1738 where it was described as the name of an idol worshiped in Africa. Its first use meaning empty talk was in 1896.