An spiritual region where certain classes of souls were supposed to await the last judgment.  [1913 Webster]

 Hence: Any real or imaginary place of restraint or confinement; a prison; as, to put a man in limbo.  [1913 Webster]

 A state of waiting, or uncertainty, in which final judgment concerning the outcome of a decision is postponed, perhaps indefinitely; neglect for an indefinite time; as, the proposal was left in limbo while opponents and proponents refused to compromise.  [PJC]

 A border or margin; as, the limbus of the cornea.  [1913 Webster]