I. -trəm noun
( plural spec·tra -rə ; or spectrums )
Etymology: New Latin, from Latin, appearance, image, specter — more at specter
1.
a. : apparition , specter
b. : afterimage
2. : an array of the components of an emission or wave separated and arranged in the order of some varying characteristic (as wavelength, mass, or energy): as
a. : a series of images formed when a beam of radiant energy is subjected to dispersion and brought to focus so that the component waves are arranged in the order of their wavelengths (as when a beam of sunlight that is refracted and dispersed by a prism forms a display of colors) — called also color spectrum
b. : electromagnetic spectrum
c. : radio spectrum
d.
(1) : the range of frequencies of sound waves to which the human ear is sensitive — called also acoustic spectrum, acoustical spectrum, sound spectrum
(2) : the range of frequencies of a particular sound (as a noise or a speech sound)
3.
a. : an intergrading array in which the constituent elements are usually not sharply isolable : a continuous sequence or range
a wide spectrum of opinions — Eugene Rabinowitch
the total spectrum of valid inference — J.T.Clark
considerable deposits of a spectrum of minerals ranging from platinum to mica — Smith Hempstone
b. : kinds of life forms associated with a particular situation (as an environmental region or sensitivity to an antibiotic) ; also : a conspectus of such forms
II. noun
1. : mass spectrum
2. : the representation (as a plot) of a spectrum