Luke 8:31, What Is The Abyss?

Question: In Luke 8:31, the Demons mention an Abyss they don't want to be cast into. Is this a Direct reference to the Abyss or Abusso that is spoken of in Revelation 17 and 20? Or is it just a deep place of some sort? Maybe the deep waters the pigs jumped into? 

 Answer: This word for 'abyss' is only used in the New Testament to refer to a holding place for fallen angels. So they are not talking about the water, but are asking to not be imprisoned in the abyss. -PJ