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A plural of spectrum.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


the plural of spectrum
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈspɛk trəm)

n., pl. -tra (-trə), -trums.
a. an array of entities, as light waves or particles, ordered in accordance with the magnitudes of a common physical property, as wavelength or mass.
b. the band or series of colors, together with invisible extensions, produced by dispersion of radiant energy, as by a prism.
2. a broad range of varied but related ideas, objects, etc., that form a continuous series or sequence: the spectrum of political beliefs.
[1605–15; < Latin: appearance, form <spec(ere) to look, regard]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in classic literature ?
"Sir,--I have read with amusement, not wholly unmixed with some less complimentary emotion, the complacent and wholly fatuous letter of James Wilson MacPhail which has lately appeared in your columns upon the subject of the blurring of Fraunhofer's lines in the spectra both of the planets and of the fixed stars.
But the spectra both from planets and stars have, in this instance, all undergone the same change.
To date, there has been no bidding for any frequency band, at least for spectra for mobile use.
Spectra Energy has also executed an agreement with Phillips 66 (NYSE: PSX) and DCP Midstream, LLC (the 50-50 joint venture between Spectra Energy and Phillips 66) under which Spectra Energy will contribute its interests in the Sand Hills and Southern Hills pipelines and Phillips 66 will contribute USD 1.5bn in cash, respectively, to DCP Midstream.
The spectra confirmed that Reichart's team had broken the record, finding the most distant gamma-ray burst ever discovered.
In a recent work ([1]) BEUTLER investigated absorption spectra of noble gases, obtaining the following results.
I had already been using a spectrum exercise with small groups on novels that had numerous characters; groups worked on different spectra (such as good to bad, pleasant to annoying, sane to insane, etc.) and then put their spectra up on the board for comparison.
The Spectra gets a new 2.0-liter DOHC engine with Continuously Variable Valve Timing (CVVT) which produces 138 hp and 136 lbs.-ft.
As an aid to vibrational spectroscopists and polymer scientists, this article discusses some of the most important commercial polymers and their infrared spectra. Identification of polymers is ideally suited to infrared analysis, but has become more difficult with the many blends of polymers that now exist.
"Customers need to lower overhead costs and streamline operations, so they demand the latest technology in an economical package to meet these objectives," says Susie Weiss, director of strategic alliances at Spectra Logic.
As the newest member of the company's Spectra family of inks, Spectra High-Strength Black and Spectra Max Black will afford customers important options and advantages in determining the products that best suits their performance needs.
To prepare it, we started with high- resolution, calibrated spectra supplied by Alexei Filippenko (University of California, Berkeley).