Definition of spectrum in English:



  • 1A band of colours, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.

    • ‘He is shown seated before his famous invention: a ruling machine for producing concave diffraction gratings, which are slightly curved metal plates scored with minutely spaced lines that diffract light into spectra.’
    • ‘He has used the spectrum of colours in the rainbow effectively to create an atmosphere of calm.’
    • ‘She wore a flowing robe of reflective black cloth with a special surface that made it reflect light in a brilliant spectrum of colors.’
    • ‘If viewed through a prism, however, there is a decomposition of the light into the colors of the spectrum, each with different wavelengths.’
    • ‘Prismatic refraction shows us the spectrum flashing out of a sort of nothing, which suggests a possible return into a single all-containing invisible source.’
    • ‘Instead, new research finds that sexual orientations exist along a continuum, like colors in the spectrum of a rainbow.’
    • ‘Visible light consists of a ‘rainbow’ or spectrum of electromagnetic waves of different wavelengths.’
    • ‘The screen is made with a patented grading, much like the ones used by scientists to view the visible light spectrum in its component colors.’
    • ‘The lights quickly alternated between blindingly bright and soothingly dimmed, while the reflective surfaces refracted lasers into spectra of color.’
    • ‘His head cocked to the side as he studied the light that bounced from the back of some of them in a rainbow spectrum.’
    • ‘Their blossoms encompass nearly the entire color spectrum and blooming times range from early spring to fall, depending on the variety.’
    • ‘A myriad of colors and textures, expertly placed, well lit candles, sending spectra of light cascading off elegantly woven rugs hanging on the walls.’
    • ‘The crystal chandeliers hanging from the ceiling, sending sparkles across the walls, rainbow spectra around the atmosphere were enchanting her in every way.’
    • ‘Thus, in the instance above cited, they have discovered the black lines which always exist in the spectrum of solar colours given by a glass prism, in the same relative places.’
    1. 1.1the spectrum The entire range of wavelengths of electromagnetic radiation.
      • ‘All the pigments absorb light energy to be used by the leaf, but each absorbs only a particular range of wavelengths, or part of the spectrum.’
      • ‘They determine which part of the spectrum would be absorbed and which would pass through unhindered.’
      • ‘The unaided eye is sensitive to just one octave out of the vast spectrum of electromagnetic radiation that exists in the universe.’
      • ‘Light, the diet of eyes, constitutes a tiny part of the entire spectrum of electromagnetic radiation.’
      • ‘The backdrop of sky passes through the entire color spectrum in seamless gradation from violet and indigo above through queasy green and luminous gold to a deep, luscious red below.’
      • ‘In the meantime over twenty presentations internationally have moved to show that across the spectrum electromagnetic fields are genotoxic, that is they damage DNA.’
      • ‘It operates in the visible and near-infrared range of the spectrum.’
      • ‘But apricot can add a spring-like touch as well, since it falls more in the yellow-orange range of the spectrum.’
      • ‘What's more, because the new light source produces white light by mixing blue, green and red, the source can emit any color in the spectrum by varying the mix.’
      • ‘The other great problem of glass envelopes is their transparency not only to light, but to much of the electro-magnetic spectrum.’
      • ‘Also of note is the way in which Melville shaded the entire film towards the blue end of the spectrum.’
      • ‘The lens filters out the blue range of the spectrum, thereby making subaquatic colors look normal.’
      • ‘Although many of them boast about how much protection they provide, according to Vanessa they will usually not cover the entire UV spectrum.’
    2. 1.2 A characteristic series of frequencies of electromagnetic radiation emitted or absorbed by a substance.
      • ‘Using a spectrometer, the transmittance spectrum is measured in a number of small regions in a stained tissue slide.’
      • ‘Extensive collections of infrared spectra, X - ray diffraction patterns and chromatograms will also be digitized and uploaded.’
      • ‘Since acupuncture points on the same meridian have similar therapeutic effects, they might be expected to have similar effects on the frequency spectrum of the arterial pulse.’
      • ‘Purified lipid-DNA adducts had a characteristic fluorescent spectra and showed a decrease of hyperchromicity and melting point.’
      • ‘We want a library of spectra from different cell types and their cancers.’
      • ‘The measurement of the wavelengths of light that are absorbed by the substance can be used to produce an absorbance spectrum of the substance.’
      • ‘Experimentally, infrared absorption spectra are obtained using infrared spectrometers.’
      • ‘The adsorption and emission of spectra characteristic of atoms also suggested that they were due to the oscillations of charged particles on the atomic or sub-atomic scale.’
      • ‘He began to classify all the known nebulae and to measure their velocities from the spectra of their emitted light.’
      • ‘The chemical bonds in Prussian blue produce a unique spectrum with FTIR analysis that can be easily distinguished from all other pigments.’
      • ‘Indeed the IR spectrum of the polymer before extrusion and after balloon manufacturing is the same.’
      • ‘This offers the option of an FFT frequency analysis to view the spectrum of the raw signal or of the distortion analyzer's residual output.’
      • ‘For those outside the field, an NMR spectrum of a typical organic molecule is a rather complex linear plot of multiple lines and peaks.’
      • ‘At that point, the differences in reflected light, or spectra, of female and male pupae were most apparent.’
      • ‘It should be noted that immunoglobulins often can be found throughout the electrophoretic spectrum.’
      • ‘One method they use, fluorescence spectroscopy, involves recording optical spectra from molecules absorbing and emitting light.’
      • ‘Already, researchers are working on satellites that can read the unique color spectrums emitted by people's skin and cameras that can tell whether people are lying by how frequently they blink.’
      • ‘Results were derived from the comparative interpretation of the conventional EEG results and the frequency spectra data, for both the experimental and control subjects.’
      • ‘Some nebulae give spectra that look like a star's, and she was familiar with them, but the Orion Nebula gave quite a different spectrum - just a single bright green line.’
      • ‘But differences in spectra led some to suspect that single bubble sonoluminescence was a distinct process from the multibubble variety.’
    3. 1.3 The components of a sound or other phenomenon arranged according to such characteristics as frequency, charge, and energy.
      • ‘Small, but significant, differences are noted between the rate spectra at both pH.’
      • ‘Cross-correlation analysis on EEG spectra and performance time series were carried out for a single participant.’
      • ‘The properties ascribed to electrons, for instance, such as their charge and half-integral spin, were themselves responses to quite specific experimental findings involving discharge tube phenomena and spectra.’
      • ‘Radio spectrum can also be mapped in other ways, onto territory.’
      • ‘The height of the spectrum indicates the extent of that frequency's contribution to the variance of the growth rate.’
      • ‘This means certain groups of atoms have similar energies, so have similar vibrational spectra.’
      • ‘The EEG frequency spectra were derived from 30 second samples that were digitized at a rate of 330 Hz, resulting in 9900 points.’
      • ‘The radio has 256 channels and emits spectrum signals that create noise, making the communication difficult to detect.’
  • 2Used to classify something in terms of its position on a scale between two extreme points.

    ‘the left or the right of the political spectrum’
    • ‘And moving to the extreme end of the spectrum, Ziv began playing at trance parties.’
    • ‘As I've suggested, they constitute a spectrum or a scale along which people take either more determined or less enthusiastic positions.’
    • ‘I recognise that these organisations are not banned as being unconstitutional but I accept the evidence of Funke that they and their members are on the extreme right of the political spectrum.’
    • ‘Other parties occupy various positions on the political spectrum.’
    • ‘There are a few on the way - on the right end of the spectrum politically, the extreme right wing, that want to keep it up there.’
    • ‘I think it is bad for Chardonnay and it is bad for the wine industry to use that term to describe a part of the political spectrum.’
    • ‘This past weekend I found myself stuck in a random debate with two people who were at one extreme end of the classic political spectrum.’
    • ‘Not bad for a man whose position on the political spectrum is roughly a million miles left to that of the average Irish voter.’
    • ‘On the other side of the political spectrum, conservatives find themselves in the position of lauding feminism as a hallmark of Western superiority.’
    • ‘Starck adds that he works for both extremes of the monetary spectrum, and that his work for ‘wealthy clients’ allows him greater freedom to design for the masses.’
    • ‘Modern biology has come to occupy an extreme position in the spectrum of the sciences, dominated by historical explanations of the evolutionary adventures of genes.’
    • ‘These candidates accepted positions covering the full spectrum of jobs within a high-technology firm.’
    • ‘Normally when giving advice one doesn't just assume that the recipient of the advice falls at the extreme of the spectrum for the field being discussed.’
    • ‘My characters and I share a similar esteem for the middle-ground, between indulgence and obligation, and any extremes of the spectrum.’
    • ‘This auction covers the whole spectrum in terms of the type of lots on offer and the estimates assigned them.’
    • ‘If Churchill is so violently attacked by both extremes of the political spectrum, we can assume that he cannot have been that bad.’
    • ‘You have two movies on extreme ends of the spectrum.’
    • ‘Journalists, across the political spectrum, publicized their position in the newspapers.’
    • ‘‘They will have to tell the people what exactly their position is in the political spectrum,’ he said.’
    • ‘But, largely thanks to the Blairite project, the gap that separates the Tories and Labour has dramatically moved its position on the political spectrum.’
    1. 2.1 A wide range.
      ‘self-help books are covering a broader and broader spectrum’
      • ‘The budding writers touched upon a wide spectrum of issues ranging from suspense, fantasy, ghosts, sporting rivalry to philosophy and science fiction.’
      • ‘Polycystic ovarian diseases have a wide spectrum of symptoms.’
      • ‘But what I think is interesting is, there's a wide spectrum of opinion about involvement in Africa, and this certainly represents it.’
      • ‘You've seen their work in a wide spectrum of venues ranging from Fast Forward to Time magazine, and now you can see it in person.’
      • ‘If he eventually wrests control of the orphans' committee, Bertrand promises to fight for more cash compensation for a wider spectrum of victims of religious abuse.’
      • ‘Interests range across a wide spectrum of sports, politics, environment, fine art, drama and community action.’
      • ‘Over the three days of public hearings the board heard from a wide spectrum of people supporting the applications and a small number of local residents and business owners who opposed them.’
      • ‘In addition to the Internet, IT covers a wide spectrum of devices ranging from embedded microprocessors to supercomputers.’
      • ‘They play a range of great music that covers a wide spectrum and their spin makes it all the more worthwhile.’
      • ‘This sense is uniting a wide spectrum of individuals and groups in asking questions not just about the so-called war on terrorism, but also about the nature of U.S. democracy.’
      • ‘Used bookstores offer a wide spectrum of genres, with best-selling novels published last year sharing the shelf with explorer's tales published over 100 years ago.’
      • ‘The point is we felt that all agencies had a fair opportunity to sell the property, that we tapped a wide spectrum of potential buyers, and came out of the deal satisfied with the overall marketing effort.’
      • ‘‘Once you are fascinated by one aspect of wildlife, you soon get attracted to the wider spectrum of wildlife,’ he says.’
      • ‘The broad scope of the show encompasses a wide spectrum of artistic styles and printmaking techniques ranging from the traditional to the innovative and modern.’
      • ‘Albeit there is a wide spectrum of orthodoxy, ranging from the devout to those who ignore the Gods.’
      • ‘I have read a wide spectrum of theories and history, ranging from Marx to Mises.’
      • ‘HBV can cause a wide spectrum of symptoms ranging from general malaise to chronic liver disease that can lead to liver cancer.’
      • ‘Economic geography supposedly has a wide spectrum of subjects, ranging from agrarian and pastoral economies to resource utilization and changes in land use.’
      • ‘We in our laboratories at CDC use a wide spectrum of tests.’
      • ‘Since the 1980s, however, a wide spectrum of Latin American opinion has come to recognize the value of democratic governance.’
      range, gamut, sweep, scope, span
      View synonyms


Early 17th century (in the sense ‘spectre’): from Latin, literally ‘image, apparition’, from specere ‘to look’.