"very filthy," 1590s, in reference to Augean stable, the cleansing of which was one of the labors of Herakles, from Greek Augeias, from Augeas, king of Elis, whose proverbially filthy stable contained 3,000 oxen and had gone uncleansed for 30 years. Herakles purified it in one day by turning the river Alpheus through it. The name probably is from auge "splendor, sunlight."