A condition or place marked by great accumulation of filth or corruption.
Example:
Leaders of many of the newly formed nations of Eastern Europe found that the old governments of their countries had become Augean stables that they must now clean out.
Augean stable most often appears in the phrase "clean the Augean stable," which usually means "clear away corruption" or "perform a large and unpleasant task that has long called for attention." Augeus, the mythical king of Elis, kept great stables that held 3,000 oxen and had not been cleaned for thirty years when Hercules was assigned the job. Thus, the word Augean by itself has come to mean "extremely difficult or distasteful," so we can also refer to Augean tasks or Augean labor, or even Augean clutter. By the way, Hercules cleaned the stables by causing two rivers to run through them.