illumination
(ɪl(j)uːmɪˈneɪʃən)
[a. F. illumination (14th c., Oresme), ad. L. illūminātiōn-em, n. of action f. illūmināre to illumine, illuminate.]
1. a. The action of illuminating; the fact or condition of being illuminated; a lighting up, a supplying of light. Also techn. in sense 1 c. of illuminate v.
circle of illumination: see circle n. 2 a.
| 1563 W. Fulke Meteors (1640) 11 Fyre scattered in the ayre, or illuminations, are generated in the lowest region of the ayre. 1603 Holland Plutarch's Mor. 1292 Mercurie..plaied at dice with the Moone, and won from her the seventieth part of every one of her illuminations. 1766 tr. Beccaria's Ess. Crimes xi. (1793) 44 The illumination of the streets during the night at the public expense. 1784 Cowper Task iv. 274 The glowing hearth may satisfy awhile With faint illumination. 1816 Playfair Nat. Phil. II. 83 The circle separating Day from Night, or the light from the dark hemisphere of the earth, is called the Circle of Illumination. 1869 Tyndall in Fortn. Rev. 1 Feb. 226 The source of illumination chosen was the electric light... The dirt and filth..were strikingly revealed by this method of illumination. 1942 J. C. Slater Microwave Transmission vi. 275 Vertically the illumination falls off gradually in intensity as the poles are approached. 1948 Pollard & Sturtevant Microwaves & Radar Electronics iv. 127 A horn feed illumination is the most widely favored. 1966 Tolstoy & Clay Ocean Acoustics vi. 199 It is convenient to measure the scattered signal relative to the signal reflected by a mirror-like surface when the illumination factor, source position, receiver position, etc., are the same. |
b. Optics. Degree of lighting up; the intensity of the light falling upon a surface, as measurable by the amount incident on each unit of the surface.
| 1863 Atkinson tr. Ganot's Physics §410 The illumination of a surface placed in a beam of parallel luminous rays is the same at all distances. 1875 Ure's Dict. Arts II. 881 Experiments for determining the relative illumination of the different lights. 1943, 1955 [see illuminance]. |
c. Directly
fig. or in
fig. context.
| 1646 Sir T. Browne Pseud. Ep. i. v. 18 Our understandings being eclipsed..we must betake our selves to wayes of reparation, and depend upon the illumination of our endeavours. 1662 Stillingfl. Orig. Sacr. ii. v. §5 Nature is sensible of..the imperfection of its own light, and therefore seems rather to require further illumination. 1825 Lamb Elia Ser. ii. Superannuated Man, The prospect..threw something of an illumination upon the darker side of my captivity. |
2. a. Spiritual enlightenment; divine inspiration;
† spec. baptism (
obs.). (The earliest sense in
Eng.)
| 1398 Trevisa Barth. De P.R. ii. viii. (MS. Harl. 614) 10 b/2 He clepeþ & bringeþ þe neþer ordris, to be parteners of þe illumynacioun of þe schynynge of god. c 1450 tr. De Imitatione iii. Contents xxvii, A praier for illuminacion of mynde. 1570 Dee Math. Pref. 15 Speciall priuiledge of Illumination, or Reuelation from heauen. 1640 Habington Castara iii. (Arb.) 112 Confounding with supernaturall illumination, the opinionated judgement of the wise. 1725 tr. Dupin's Eccl. Hist. 17th C. I. v. 57 Besides the Name of Baptism..they gave it also the Name of Illumination, of Light, of Circumcision. 1845 H. J. Rose Theology in Encycl. Metrop. II. 872/1 Ecclesiastical History gives us several instances of similar claims to prophecy and divine illumination. 1857 Keble Eucharist. Adorat. 15 In baptism we are illuminated, in illumination adopted. |
b. pl. An instance of this; an inspiration; a revelation.
| c 1340 Hampole Prose Tr. 17 Þe deuelle entirs þan by fals illumynacyons, and fals sownnes and swetnes, and dyssaues a mans saule. 1634 Sir T. Herbert Trav. 220 Madoc ingeniously perusing the older illuminations and seeing in some things the prophecie of this authentique Bardh. 1764 Harmer Observ. ix. vi. 250 Worship God..to Whom in justice you ought to ascribe these illuminations. 1878 C. Stanford Symb. Christ i. 12 Whose soul was..visited with preternatural illuminations. |
3. Intellectual enlightenment; information, learning;
† occas. in
pl., intellectual gifts. Also, the ‘enlightenment’ or doctrines of the
Illuminati.
| 1634 Sir T. Herbert Trav. 12 They [Columbus and Americus] had an Antecessor from whose writings and Plats they had their illuminations. 1658 Evelyn Diary 27 Jan., These and the like illuminations, far exceeded his age. 1692 Ray Dissol. World iii. ix. (1732) 401 After further Illumination they were better informed. 1862 Lewes Stud. Anim. Life i. 41 From the illumination of many minds on many points, Truth must finally emerge. 1881 J. C. Shairp Aspects Poetry iv. 105 To turn the tide against the Illumination, of which Voltaire, Diderot, and the host of Encyclopædists were the high priests. 1886 Dowden Shelley I. 534 The materialistic philosophers of the French Illumination. 1893 Sir R. Ball Story of Sun 75 The illumination which mathematics alone can afford. |
4. a. The lighting up of a building, town, etc. (now usually in a decorative way, with coloured lights arranged in artistic designs, etc.), in token of festivity or rejoicing.
b. with
an and
pl. An instance of this; also
pl. the lights, or figures composed of lights, used in such decoration.
| 1691 Luttrell Brief Rel. (1857) II. 293 With many bone⁓fires and illuminations at night. 1698 Fryer Acc. E. India & P. 94 A Time of Solemnity sometimes kept for several Weeks together with Illuminations on their Houses. 1767 Franklin Lett. Wks. 1887 IV. 39 At the Church of Notre Dame, where we went to see a magnificent illumination, with figures, etc. 1823 Byron Juan vii. xliv, When London had a grand illumination..So that the streets of colour'd lamps are full. 1864 Daily Tel. 20 Sept., The illuminations were really magnificent. |
| attrib. 1797 Mrs. Radcliffe Italian xiii, It was an illumination night. |
† 5. Elucidation.
Obs. rare—1.
| 1656 B. Harris Parival's Iron Age i. xvi. 32 For the restauration of learning, and for the illumination and illustration of Sciences. 1658 Phillips, Illumination, the same [as Illucidation, an explaining or making clear]. |
6. a. The embellishment or decoration of a letter or writing with bright or luminous colours, the use of gold and silver, the addition of elaborate tracery or miniature illustrations, etc.: see
illuminate v. 8.
b. with
pl. The designs, miniatures, and the like, employed in such decoration.
† c. Formerly, also, the colouring of maps or prints.
| 1678 Phillips (ed. 4), Illumination,..a laying colours upon Maps or Printed Pictures; so as to give the greater light, as it were, and beauty to them. 1856 Ruskin Mod. Paint. III. iv. viii. §9 The distinctive difference between illumination and painting proper, being, that illumination admits no shadows, but only gradations of pure colour. 1858 Hawthorne Fr. & It. Jrnls. II. 112 Beautiful illuminations, the vermilion and gold of which looked as brilliant now as they did five centuries ago. 1870 Ruskin Lect. Art v. 138 Perfect illumination is only writing made lovely; the moment it passes into picture making it has lost its dignity and function. |