出典:Wiktionary
From Augean (“pertaining to Augeas”) + stables. Augeas was a legendary king of Elis in Greek mythology who owned 3,000 divine cattle which produced a huge amount of dung in stables that had not been cleaned for over 30 years. The cleaning of the stables was the fifth of the twelve Labours of Hercules, which Hercules achieved by rerouting the Alpheus and Peneus rivers through them.[1]
Augean stables pl (normally 複数形, 単数形 Augean stable) (idiomatic)