Jamieson, Fausset and Brown on Ephesians 5:3

3. once named--Greek, "Let it not be even named" (Ep 5:4, 12). "Uncleanness" and "covetousness" are taken up again from Ep 4:19. The two are so closely allied that the Greek for "covetousness" (pleonexia) is used sometimes in Scripture, and often in the Greek Fathers, for sins of impurity. The common principle is the longing to fill one's desire with material objects of sense, outside of God. The expression, "not be even named," applies better to impurity, than to "covetousness."