spectrum

• POS: Noun
• HYPHEN: spec=trum

CIDE DICTIONARY

spectrum, n. [L. See Specter.].

•  An apparition; a specter.  [1913 Webster]
•  The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed or studied either as spread out on a screen, by direct vision, by photography, or otherwise. See Illust. of Light, and Spectroscope.  [1913 Webster]

Absorption spectrum, the spectrum of light which has passed through a medium capable of absorbing a portion of the rays. It is characterized by dark spaces, bands, or lines. -- Chemical spectrum, a spectrum of rays considered solely with reference to their chemical effects, as in photography. These, in the usual photogrophic methods, have their maximum influence at and beyond the violet rays, but are not limited to this region. -- Chromatic spectrum, the visible colored rays of the solar spectrum, exhibiting the seven principal colors in their order, and covering the central and larger portion of the space of the whole spectrum. -- Continous spectrum, a spectrum not broken by bands or lines, but having the colors shaded into each other continously, as that from an incandescent solid or liquid, or a gas under high pressure. -- Diffraction spectrum, a spectrum produced by diffraction, as by a grating. -- Gaseous spectrum, the spectrum of an incandesoent gas or vapor, under moderate, or especially under very low, pressure. It is characterized by bright bands or lines. -- Normal spectrum, a representation of a spectrum arranged upon conventional plan adopted as standard, especially a spectrum in which the colors are spaced proportionally to their wave lengths, as when formed by a diffraction grating. -- Ocular spectrum. See Spectrum, 2 (b), above. -- Prismatic spectrum, a spectrum produced by means of a prism. -- Solar spectrum, the spectrum of solar light, especially as thrown upon a screen in a darkened room. It is characterized by numerous dark lines called Fraunhofer lines. -- Spectrum analysis, chemical analysis effected by comparison of the different relative positions and qualities of the fixed lines of spectra produced by flames in which different substances are burned or evaporated, each substance having its own characteristic system of lines. -- Thermal spectrum, a spectrum of rays considered solely with reference to their heating effect, especially of those rays which produce no luminous phenomena.

OXFORD DICTIONARY

spectrum, n. (pl. spectra)
1 the band of colours, as seen in a rainbow etc., arranged in a progressive series according to their refrangibility or wavelength.
2 the entire range of wavelengths of electromagnetic radiation.
3 a an image or distribution of parts of electromagnetic radiation arranged in a progressive series according to wavelength. b this as characteristic of a body or substance when emitting or absorbing radiation.
4 a similar image or distribution of energy, mass, etc., arranged according to frequency, charge, etc.
5 the entire range or a wide range of anything arranged by degree or quality etc.
6 (in full ocular spectrum) an after-image.

Idiom

spectrum (or spectral) analysis chemical analysis by means of a spectroscope.

Etymology

L, = image, apparition f. specere look

THESAURUS

spectrum

AF, CPS, Dalmatian, EHF, HF, Hz, Indian file, MF, Maxwell triangle, Munsell scale, RF, SHF, UHF, VHF, VLF, afterimage, antigorite, array, articulation, audio frequency, bank, bogey, butterfly, buzz, candy cane, carrier frequency, carry, catena, catenation, chain, chain reaction, chaining, chameleon, cheetah, chromatic circle, chromatic spectrum, chromaticity diagram, chrysotile, color circle, color cycle, color index, color mixture curve, color solid, color spectrum, color system, color triangle, compass, complementary color, concatenation, confetti, connection, consecution, continuum, course, crazy quilt, cycle, cycles, demitint, descent, diapason, drone, eidolon, endless belt, endless round, extremely high frequency, file, filiation, firedog, frequency, frequency spectrum, full color, fundamental colors, gamut, ghost, gradation, half tint, halftone, harlequin, haunt, hertz, high frequency, hue cycle, hum, intermediate frequency, iris, jaguar, kilocycles, kilohertz, leopard, line, lineage, low frequency, lower frequencies, mackerel, mackerel sky, marble, marbled paper, medium frequency, megacycles, megahertz, metamer, moire, monochrome, monotone, mother-of-pearl, nacre, nexus, ocelot, ocular spectrum, opal, ophite, optical illusion, patchwork quilt, peacock, pendulum, periodicity, phantasm, plenum, powder train, primary, primary color, progression, pure color, queue, radio frequency, radius, rainbow, range, rank, reach, recurrence, register, reticulation, revenant, rotation, round, routine, row, run, scale, scope, secondary, secondary color, sequence, series, serpentine, serpentine marble, shade, shot silk, single file, solar spectrum, spark frequency, spectral color, spectrum color, spirit, spook, stretch, string, succession, superhigh frequency, swath, sweep, tertiary, tertiary color, thread, tier, tortoise shell, train, trick of eyesight, ultrahigh frequency, upper frequencies, very high frequency, very low frequency, windrow, zebra

ROGET THESAURUS

spectrum

Color

N color, hue, tint, tinge, dye, complexion, shade, tincture, cast, livery, coloration, glow, flush, tone, key, pure color, positive color, primary color, primitive complementary color, three primaries, spectrum, chromatic dispersion, broken color, secondary color, tertiary color, local color, coloring, keeping, tone, value, aerial perspective, chromatics, spectrum analysis, spectroscopy, chromatism, chromatography, chromatology, prism, spectroscope, spectrograph, spectrometer, colorimeter (optical instruments), pigment, coloring matter, paint, dye, wash, distemper, stain, medium, mordant, oil paint, colored, colorific, tingent, tinctorial, chromatic, prismatic, full-colored, high-colored, deep-colored, doubly-dyed, polychromatic, chromatogenous, tingible, bright, vivid, intense, deep, fresh, unfaded, rich, gorgeous, gay, gaudy, florid, gay, garish, rainbow-colored, multihued, showy, flaunting, flashy, raw, crude, glaring, flaring, discordant, inharmonious, mellow, pastel, harmonious, pearly, sweet, delicate, tender, refined.

Variegation

N variegation, colors, dichroism, trichroism, iridescence, play of colors, polychrome, maculation, spottiness, striae, spectrum, rainbow, iris, tulip, peacock, chameleon, butterfly, tortoise shell, mackerel, mackerel sky, zebra, leopard, cheetah, nacre, ocelot, ophite, mother-of-pearl, opal, marble, check, plaid, tartan, patchwork, marquetry-, parquetry, mosaic, tesserae, strigae, chessboard, checkers, chequers, harlequin, Joseph's coat, tricolor, variegated, many-colored, many-hued, divers-colored, party- colored, dichromatic, polychromatic, bicolor, tricolor, versicolor, of all the colors of the rainbow, of all manner of colors, kaleidoscopic, iridescent, opaline, opalescent, prismatic, nacreous, pearly, shot, gorge de pigeon, chatoyant, irisated, pavonine, pied, piebald, motley, mottled, marbled, pepper and salt, paned, dappled, clouded, cymophanous, mosaic, tesselated, plaid, tortoise shell, spotted, spotty, punctated, powdered, speckled, freckled, flea-bitten, studded, flecked, fleckered, striated, barred, veined, brinded, brindled, tabby, watered, grizzled, listed, embroidered, daedal, naevose, stipiform, strigose, striolate, (iii) PERCEPTIONS OF LIGHT.

Dimsightedness

N dimsightedness, dim sight, dull sight half sight, short sight, near sight, long sight, double sight, astigmatic sight, failing sight, dimsightedness, purblindness, lippitude, myopia, presbyopia, confusion of vision, astigmatism, color blindness, chromato pseudo blepsis, Daltonism, nyctalopia, strabismus, strabism, squint, blearedness, day blindness, hemeralopia, nystagmus, xanthocyanopia, xanthopsia, cast in the eye, swivel eye, goggle-eyes, obliquity of vision, winking, nictitation, blinkard, albino, dizziness, swimming, scotomy, cataract, ophthalmia, blinker, screen, deceptio visus, refraction, distortion, illusion, false light, anamorphosis, virtual image, spectrum, mirage, looming, phasma, phantasm, phantasma, phantom, vision, specter, apparition, ghost, ignis fatuus, specter of the Brocken, magic mirror, magic lantern, mirror lens, dim-sighted, myopic, presbyopic, astigmatic, moon-eyed, mope-eyed, blear-eyed, goggle-eyed, gooseberry-eyed, one-eyed, blind of one eye, monoculous, half-blind, purblind, cock-eyed, dim-eyed, mole- eyed, dichroic, blind as a bat, winking.