Definition for spectra (2 of 2)
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
Examples from the Web for spectra
The result is a mosaic of spectra, covering up to 60 different regions.
In this way the two spectra are seen side by side and the dark and bright lines can be compared accurately together (see Fig. 50).Through Magic Glasses and Other Lectures|Arabella B. Buckley
I have attended to this frequently, when I have observed my eyes more than commonly sensible to other spectra.Zoonomia, Vol. I|Erasmus Darwin
Not the slightest difference could be seen between any of the lines in the two spectra.
British Dictionary definitions for spectra (1 of 2)
British Dictionary definitions for spectra (2 of 2)
noun plural -tra (-trə)
Word Origin for spectrum
Word Origin and History for spectra
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.