'Polemonium coeruleum having corymbs of drooping flowers usually blue Gray' definitions:

Definition of 'Polemonium coeruleum having corymbs of drooping flowers usually blue Gray'

From: GCIDE

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]