[a. Heb. yasăqōb, in Gr. Ἰακωβος, L. Jacōbus, whence also came Eng. James.] A personal name and surname; used also in derived and transferred senses, partly referring to JACOB’S LADDER.
† 1. = JACOBUS, the gold coin. Obs.
1662. Pepys, Diary, 23 Nov. A poulterer … hath left £800 per annum … and 40,000 Jacobs in gold.
† 2. slang. a. A housebreaker carrying a ladder.
1712–53. Thief-Catcher, 25. Rogues called Jacobs; these go with Ladders in the Dead of the Night, and get in at the Windows.
b. A ladder.
1708. Mem. John Hall, 21. Jacob, a Ladder.
1796. Grose, Dict. Vulgar T., Jacob, a ladder: perhaps from Jacob’s dream.
1803. Sporting Mag., XII. 54. A Jacob is a ladder.
c. A simpleton.
1811. Lex. Bal., Jacob. A soft fellow. A fool.
1812. J. H. Vaux, Flash Dict., Jacob,… a simple half-witted person.
3. The possessive Jacob’s occurs in the following: Jacob’s coat, membrane (Anat.), the layer of rods and cones of the retina of the eye (named after Arthur Jacob, an Irish ophthalmic surgeon, died 1874); Jacob’s shell, the scallop-shell Pecten Jacobæus, the emblem of St. James the Greater, and worn by pilgrims who had visited his shrine; Jacob’s stone, a name applied to the coronation stone of the Scottish kings at Scone, now in Westminster Abbey, fabled to be the stone of Jacob’s pillow (Gen. xxviii. 11); Jacob’s ulcer, ‘a term for Lupus or rodent ulcer of the eye’ (from Arthur Jacob, above-named). Also JACOB’S LADDER, JACOB’S STAFF.
1842. E. Wilson, Anat. Vade M., 453. *Jacob’s Membrane … is seen as a flocculent film when the eye is suspended in water.
1879. Harlan, Eyesight, ii. 18. This external layer, called Jacob’s membrane.
1756–7. trans. Keysler’s Trav. (1760), III. 212. In the Adriatic are likewise found the species called *Jacob’s shells, or Pectines.
1637. Heywood, Royal King, I. i. Wks. 1874, VI. 7. If I survive Englands Inheritance, Or euer live to sit on *Iacob’s Stone.
