▪ I. ‖ umbra1
(ˈʌmbrə)
Pl. umbræ (ˈʌmbriː).
[L. umbra shade, shadow, umber n.1 Cf. It. ombra, ombria, F. ombre.]
1. The shade of a deceased person; a phantom or ghost. Also fig.
| 1599 B. Jonson Cynthia's Rev. Induct., The umbræ or ghosts of some three or four playes, departed a dozen yeeres since. 1654 Gayton Pleas. Notes iii. iii. 78 Such kind of Tones as these the Umbræ use, when they call upon Charon for a Boat. 1654 tr. Scudery's Curia Pol. Pref., I have not troubled their famous umbra's, whom an innocent kind of Magick hath so often summoned from their Royal Tombs. 1878 Besant & Rice Celia's Arb. xi, The faint and dimly-seen ghost of a possible repentance,..a special umbra pointing heavenward. 1883 Sat. Rev. 21 Apr. 486/1 Had Lord Beaconsfield ever indulged in such rashness, his umbra might point out..the disaster and the disgrace which have followed on their neglect of the warning. |
b. (See quot.)
| a 1652 J. Smith Sel. Disc. v. 176 The spiritual vehicle of the soul,..a kind of umbra or aërial mantle in which the soul wraps herself. |
2. A mere shadow of something. In quot. fig.
| 1634 Rainbow Labour (1635) 33 The pride of those..who are their owne umbra's, the servants and shadowes of their owne reflected shadowes. |
b. An uninvited guest accompanying one who is invited.
| 1696 S. Sewall Diary 7 May, And let my dear Wife and all my children partake in this priviledge, and that not as Umbras, but on their own account. 1724 Moffet Hesperineso-gr. (1755) 9 Most of the guests their umbra's brought And sauce that money never bought. c 1800 R. Cumberland John De Lancaster (1809) II. 71 Mr. David Owen and his umbra in the bottle green were missing. 1834 Lytton Pompeii i. iii, The sixth banqueter, who was the umbra of Clodius,..muttered also ‘ædepol’. |
3. Shade; shadow.
| 1638 Sir T. Herbert Trav. (ed. 2) 5 To all in the temperate Zone, in the Sunnes Meridian their shadowes cast North, having past the Zenith, the shade or umbra becomes contrary. 1856 Ruskin Mod. Paint. IV. v. v. §11 If any of these wayward umbræ are faithfully remembered and set down by the painter, they nearly always have an unaccountable look. |
4. Astr. a. The shadow cast by the earth or moon as visible in an eclipse; now spec. that portion in which the shadow is complete, as contrasted with the penumbra.
| 1679 Moxon Math. Dict., Umbra, a shadow, a word oft used in the obscuration [sic] of Eclipses. 1812 Woodhouse Astron. xxxv. 344 The cones of the umbra and penumbra..formed by lines drawn from the Sun and touching the Earth's surface. 1833 Herschel Astron. vi. 225 Owing to the great size of the earth, the cone of its umbra always projects far beyond the moon. 1868 Lockyer Elem. Astron. §237 If the Sun were a point of light merely, the shadow would be all umbra. |
b. In sun-spots: (see quots.).
The earlier nucleus and umbra correspond respectively to the modern umbra and penumbra.
| 1788 Encycl. Brit. (ed. 3) II. 434/2 The increase of a spot is gradual, the breadth of the nucleus and umbra dilating at the same time. Ibid., Small umbræ are often seen without nuclei. 1860 Olmsted Mech. Heavens x. 103 A solar spot usually consists of two parts, the nucleus and the umbra... The umbra is a wide margin, of lighter shade, and is often of greater extent than the nucleus. 1868 Lockyer Guillemin's Heavens (ed. 3) 32 The spots consist almost invariably of one or several dark portions called umbræ, which seem black when compared with the luminous parts of the disk. 1878 Newcomb Pop. Astron. iii. ii. 245 The shaded penumbra seems to form the sides of the cavity, while the umbra is the invisible bottom. |
5. Algebra. A symbol which requires to be paired with another in order to denote a quantity.
| 1851 Sylvester in Lond. etc. Phil. Mag. Apr. 296 Each quantity is now represented by two letters; the letters themselves, taken separately, being symbols neither of quantity nor of operation, but mere umbræ or ideal elements of quantitative symbols. 1855 Rankine Misc. Sci. Papers (1881) 139 The tasinomic coefficients for oblique axes may be regarded as compounded of umbræ. |
▪ II. ‖ ˈumbra2 rare.
[L. umbra, perh. the same word as prec.]
1. The grayling; = umber n.2
| 1610 Holland Camden's Brit. 627 Both these rivers are full of salmons and trouts, but Wy of the twaine is the better, affording the best kind of them which they call Vmbras. 1708 Kersey, Umbra,..the Vmber, a sort of Fish. 1769 Pennant Brit. Zool. III. 262 It is a very swift swimmer and disappears like the transient passage of a shadow, from whence we believe is derived the name of Umbra. |
2. A sciænoid fish of the genus Umbrina, esp. the Mediterranean species U. cirrosa.
| 1753 Chambers' Cycl. Suppl. s.v. 1755 Dict. Arts & Sci., Sciæna,..this genus comprehends the umbra and the umbrino. 1854 Badham Halieut. 43 A sandy bottom, though not absolutely bad for flat fish, suits the pelagians..best; such as, e.g. auratas, the dentex, and Punic and indigenous umbras. |
▪ III. umbra
obs. form of omrah.