noun, plural spec·tra [spek-truh] /ˈspɛk trə/, spec·trums.
- an array of entities, as light waves or particles, ordered in accordance with the magnitudes of a common physical property, as wavelength or mass: often the band of colors produced when sunlight is passed through a prism, comprising red, orange, yellow, green, blue, indigo, and violet.
- this band or series of colors together with extensions at the ends that are not visible to the eye, but that can be studied by means of photography, heat effects, etc., and that are produced by the dispersion of radiant energy other than ordinary light rays.Compare band spectrum, electromagnetic spectrum, mass spectrum.
Origin of spectrum
Related Words for spectrascope, gamut, sphere, range, continuum, rainbow, scale, span, sweep, field, extent, compass, series, colors, distribution, sequence
Examples from the Web for spectra
Contemporary Examples of spectra
The result is a mosaic of spectra, covering up to 60 different regions.SAMI Is Like Google Earth for the Universe
Matthew R. Francis
July 27, 2014
Historical Examples of spectra
One of the spectra had dark lines and the other bright lines.Pleasures of the telescope
With 188 Illustrations and a table of Spectra in Chromo-lithography.An Outline of English Speech-craft
Their spectra show a complexity of helium and hydrogen bands.
The spectra of all the Algol variables are of the first or Sirian type.
In the same manner and under similar conditions the spectra of many other substances have been reversed.
noun plural -tra (-trə)
Word Origin for spectrum
1610s, "apparition, specter," from Latin spectrum "appearance, image, apparition," from specere "to look at, view" (see scope (n.1)). Meaning "band of colors formed from a beam of light" first recorded 1670s.