spec ‧ trum /ˈspektrəm/ BrE AmE noun ( plural spectra /-trə/) [countable]
[ Date: 1800-1900 ; Language: Latin ; Origin: 'something that appears, image' , from specere 'to look (at)' ]
1 . a complete range of opinions, people, situations etc, going from one extreme to its opposite
the ethnic spectrum of America
across the spectrum
The bill drew support from across the political spectrum.
broad/wide/full etc spectrum
a broad spectrum of environmental groups
The two articles here represent opposite ends of the spectrum.
2 . the set of bands of coloured light into which a beam of light separates when it is passed through a ↑ prism
3 . a complete range of radio, sound etc waves:
the electromagnetic spectrum