Meaning of SPECTRUM in English
/ ˈspektrəm; NAmE / noun ( pl. spec·tra / ˈspektrə; NAmE /)
a band of coloured lights in order of their wavelengths , as seen in a rainbow and into which light may be separated :
A spectrum is formed by a ray of light passing through a prism.
Red and violet are at opposite ends of the spectrum.
a range of sound waves or several other types of wave :
the electromagnetic / radio / sound spectrum
[ usually sing. ] a complete or wide range of related qualities, ideas, etc. :
a broad spectrum of interests
We shall hear views from across the political spectrum.
early 17th cent. (in the sense spectre ): from Latin , literally image, apparition , from specere to look.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005