Source : Webster's Revised Unabridged Dictionary (1913)

Limbo \Lim"bo\ (l[i^]m"b[-o]), Limbus \Lim"bus\ (-b[u^]s), n.
   [L. limbus border, edge, in limbo on the border. Cf. {Limb}
   border.]
   1. (Scholastic Theol.) An extramundane region where certain
      classes of souls were supposed to await the judgment.

            As far from help as Limbo is from bliss. --Shak.

            A Limbo large and broad, since called The Paradise
            of fools.                             --Milton.

   Note: The limbus patrum was considered as a place for the
         souls of good men who lived before the coming of our
         Savior. The limbus infantium was said to be a similar
         place for the souls of unbaptized infants. To these was
         added, in the popular belief, the limbus fatuorum, or
         fool's paradise, regarded as a receptacle of all vanity
         and nonsense.

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

Source : WordNet®

limbo
     n 1: the state of being disregarded or forgotten [syn: {oblivion}]
     2: an imaginary place for lost or neglected things
     3: (theology) in Roman Catholicism, the place of unbaptized but
        innocent or righteous souls (such as infants and virtuous
        individuals)