Main Entry: spec·trum

Pronunciation: \ˈspek-trəm\

Function: noun

Inflected Form(s): plural spec·tra \-trə\ or spectrums

Etymology: New Latin, from Latin, appearance — more at specter

Date: 1671

1 a : a continuum of color formed when a beam of white light is dispersed (as by passage through a prism) so that its component wavelengths are arranged in order b : any of various continua that resemble a color spectrum in consisting of an ordered arrangement by a particular characteristic (as frequency or energy): as (1) : electromagnetic spectrum (2) : radio spectrum (3) : the range of frequencies of sound waves (4) : mass spectrum c : the representation (as a plot) of a spectrum
2 a : a continuous sequence or range <a wide spectrum of interests> <opposite ends of the political spectrum> b : kinds of organisms associated with a particular situation (as an environment) c : a range of effectiveness against pathogenic organisms <an antibiotic with a broad spectrum>