The Collaborative International Dictionary of English v.0.48:

Jacob \Ja"cob\, n. [Cf. F. Jacob. See 2d Jack.]
   A Hebrew patriarch (son of Isaac, and ancestor of the Jews),
   who in a vision saw a ladder reaching up to heaven (--Gen.
   xxviii. 12); -- also called Israel.
   [1913 Webster]

         And Jacob said . . . with my staff I passed over this
         Jordan, and now I am become two bands.   --Gen. xxxii.
                                                  9, 10.
   [1913 Webster]

         Thy name shall be called no more Jacob, but Israel.
                                                  --Gen. xxxii.
                                                  28.
   [1913 Webster]

   Jacob's ladder.
   (a) (Bot.) A perennial herb of the genus Polemonium
       (Polemonium c[oe]ruleum), having corymbs of drooping
       flowers, usually blue. Gray.
   (b) (Naut.) A rope ladder, with wooden steps, for going
       aloft. --R. H. Dana, Jr.
   (c) (Naut.) A succession of short cracks in a defective spar.


   Jacob's membrane. See Retina.

   Jacob's staff.
   (a) A name given to many forms of staff or weapon, especially
       in the Middle Ages; a pilgrim's staff. [Obs.] --Spenser.
   (b) (Surveying) See under Staff.
       [1913 Webster]

WordNet (r) 3.0 (2006):

Israel
    n 1: Jewish republic in southwestern Asia at eastern end of
         Mediterranean; formerly part of Palestine [syn: Israel,
         State of Israel, Yisrael, Zion, Sion]
    2: an ancient kingdom of the Hebrew tribes at the southeastern
       end of the Mediterranean Sea; founded by Saul around 1025 BC
       and destroyed by the Assyrians in 721 BC