Polemonium coeruleum having corymbs of drooping flowers usually blue Gray

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]