The earliest discussion (approximately 495 A.D. in the works of John Cassian) of the “seven deadly” sins were actually eight sins:
the struggle against the eight principal faults, i.e. first, Gluttony or the pleasures of the palate; secondly, Fornication; thirdly, Covetousness, which means Avarice, or, as it may more properly be called, the love of money, fourthly, Anger; fifthly, Dejection; sixthly, “Accidie,”4 which is heaviness or weariness of heart; seventhly, κενοδοξία which means foolish or vain glory; eighthly, pride.
John Cassian, “The Twelve Books of John Cassian on the Institutes of the Cœnobia,” in Sulpitius Severus, Vincent of Lérins, John Cassian, ed. Philip Schaff and Henry Wace, trans. Edgar C. S. Gibson, vol. 11, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, Second Series (New York: Christian Literature Company, 1894), 233–234.