Definition of spectrum in English:


nounPlural spectra, Plural spectrums

  • 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.

    • ‘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.’
    • ‘Visible light consists of a ‘rainbow’ or spectrum of electromagnetic waves of different wavelengths.’
    • ‘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.’
    • ‘She wore a flowing robe of reflective black cloth with a special surface that made it reflect light in a brilliant spectrum of colors.’
    • ‘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.’
    • ‘His head cocked to the side as he studied the light that bounced from the back of some of them in a rainbow spectrum.’
    • ‘The crystal chandeliers hanging from the ceiling, sending sparkles across the walls, rainbow spectra around the atmosphere were enchanting her in every way.’
    • ‘The lights quickly alternated between blindingly bright and soothingly dimmed, while the reflective surfaces refracted lasers into spectra of color.’
    • ‘Their blossoms encompass nearly the entire color spectrum and blooming times range from early spring to fall, depending on the variety.’
    • ‘He has used the spectrum of colours in the rainbow effectively to create an atmosphere of calm.’
    • ‘If viewed through a prism, however, there is a decomposition of the light into the colors of the spectrum, each with 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.’
    • ‘Instead, new research finds that sexual orientations exist along a continuum, like colors in the spectrum of a rainbow.’
    • ‘A myriad of colors and textures, expertly placed, well lit candles, sending spectra of light cascading off elegantly woven rugs hanging on the walls.’
    1. 1.1the spectrum The entire range of wavelengths of electromagnetic radiation.
      • ‘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.’
      • ‘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.’
      • ‘Light, the diet of eyes, constitutes a tiny part of the entire spectrum 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.’
      • ‘The unaided eye is sensitive to just one octave out of the vast spectrum of electromagnetic radiation that exists in the universe.’
      • ‘Although many of them boast about how much protection they provide, according to Vanessa they will usually not cover the entire UV spectrum.’
      • ‘Also of note is the way in which Melville shaded the entire film towards the blue end 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.’
      • ‘They determine which part of the spectrum would be absorbed and which would pass through unhindered.’
      • ‘The lens filters out the blue range of the spectrum, thereby making subaquatic colors look normal.’
      • ‘It operates in the visible and near-infrared range of the spectrum.’
    2. 1.2 A characteristic series of frequencies of electromagnetic radiation emitted or absorbed by a substance.
      • ‘The measurement of the wavelengths of light that are absorbed by the substance can be used to produce an absorbance spectrum of the substance.’
      • ‘For those outside the field, an NMR spectrum of a typical organic molecule is a rather complex linear plot of multiple lines and peaks.’
      • ‘Results were derived from the comparative interpretation of the conventional EEG results and the frequency spectra data, for both the experimental and control subjects.’
      • ‘Extensive collections of infrared spectra, X - ray diffraction patterns and chromatograms will also be digitized and uploaded.’
      • ‘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.’
      • ‘Using a spectrometer, the transmittance spectrum is measured in a number of small regions in a stained tissue slide.’
      • ‘He began to classify all the known nebulae and to measure their velocities from the spectra of their emitted light.’
      • ‘Purified lipid-DNA adducts had a characteristic fluorescent spectra and showed a decrease of hyperchromicity and melting point.’
      • ‘But differences in spectra led some to suspect that single bubble sonoluminescence was a distinct process from the multibubble variety.’
      • ‘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.’
      • ‘One method they use, fluorescence spectroscopy, involves recording optical spectra from molecules absorbing and emitting light.’
      • ‘At that point, the differences in reflected light, or spectra, of female and male pupae were most apparent.’
      • ‘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.’
      • ‘The chemical bonds in Prussian blue produce a unique spectrum with FTIR analysis that can be easily distinguished from all other pigments.’
      • ‘It should be noted that immunoglobulins often can be found throughout the electrophoretic spectrum.’
      • ‘Indeed the IR spectrum of the polymer before extrusion and after balloon manufacturing is the same.’
      • ‘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.’
      • ‘We want a library of spectra from different cell types and their cancers.’
      • ‘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.’
      • ‘Experimentally, infrared absorption spectra are obtained using infrared spectrometers.’
    3. 1.3 The components of a sound or other phenomenon arranged according to such characteristics as frequency, charge, and energy.
      • ‘Radio spectrum can also be mapped in other ways, onto territory.’
      • ‘The EEG frequency spectra were derived from 30 second samples that were digitized at a rate of 330 Hz, resulting in 9900 points.’
      • ‘This means certain groups of atoms have similar energies, so have similar vibrational spectra.’
      • ‘The height of the spectrum indicates the extent of that frequency's contribution to the variance of the growth rate.’
      • ‘Small, but significant, differences are noted between the rate spectra at both pH.’
      • ‘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.’
      • ‘Cross-correlation analysis on EEG spectra and performance time series were carried out for a single participant.’
      • ‘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’
    • ‘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.’
    • ‘‘They will have to tell the people what exactly their position is in the political spectrum,’ he said.’
    • ‘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.’
    • ‘Journalists, across the political spectrum, publicized their position in the newspapers.’
    • ‘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.’
    • ‘Not bad for a man whose position on the political spectrum is roughly a million miles left to that of the average Irish voter.’
    • ‘But, largely thanks to the Blairite project, the gap that separates the Tories and Labour has dramatically moved its position on the political spectrum.’
    • ‘And moving to the extreme end of the spectrum, Ziv began playing at trance parties.’
    • ‘This auction covers the whole spectrum in terms of the type of lots on offer and the estimates assigned them.’
    • ‘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.’
    • ‘These candidates accepted positions covering the full spectrum of jobs within a high-technology firm.’
    • ‘You have two movies on extreme ends of the spectrum.’
    • ‘As I've suggested, they constitute a spectrum or a scale along which people take either more determined or less enthusiastic positions.’
    • ‘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.’
    • ‘Other parties occupy various positions on the political spectrum.’
    • ‘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.’
    • ‘On the other side of the political spectrum, conservatives find themselves in the position of lauding feminism as a hallmark of Western superiority.’
    • ‘If Churchill is so violently attacked by both extremes of the political spectrum, we can assume that he cannot have been that bad.’
    • ‘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.’
    1. 2.1 A wide range.
      ‘self-help books are covering a broader and broader spectrum’
      • ‘But what I think is interesting is, there's a wide spectrum of opinion about involvement in Africa, and this certainly represents it.’
      • ‘Polycystic ovarian diseases have a wide spectrum of symptoms.’
      • ‘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.’
      • ‘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.’
      • ‘Economic geography supposedly has a wide spectrum of subjects, ranging from agrarian and pastoral economies to resource utilization and changes in land use.’
      • ‘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.’
      • ‘Since the 1980s, however, a wide spectrum of Latin American opinion has come to recognize the value of democratic governance.’
      • ‘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.’
      • ‘We in our laboratories at CDC use a wide spectrum of tests.’
      • ‘The budding writers touched upon a wide spectrum of issues ranging from suspense, fantasy, ghosts, sporting rivalry to philosophy and science fiction.’
      • ‘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.’
      • ‘In addition to the Internet, IT covers a wide spectrum of devices ranging from embedded microprocessors to supercomputers.’
      • ‘‘Once you are fascinated by one aspect of wildlife, you soon get attracted to the wider spectrum of wildlife,’ he says.’
      • ‘Interests range across a wide spectrum of sports, politics, environment, fine art, drama and community action.’
      • ‘Albeit there is a wide spectrum of orthodoxy, ranging from the devout to those who ignore the Gods.’
      • ‘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.’
      • ‘They play a range of great music that covers a wide spectrum and their spin makes it all the more worthwhile.’
      • ‘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.’
      • ‘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.’
      range, gamut, sweep, scope, span
      View synonyms


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