|—n , pl -tra|
|1.||the distribution of colours produced when white light is dispersed by a prism or diffraction grating. There is a continuous change in wavelength from red, the longest wavelength, to violet, the shortest. Seven colours are usually distinguished: violet, indigo, blue, green, yellow, orange, and red|
|2.||the whole range of electromagnetic radiation with respect to its wavelength or frequency|
|3.||absorption spectrum See also emission spectrum any particular distribution of electromagnetic radiation often showing lines or bands characteristic of the substance emitting the radiation or absorbing it|
|4.||any similar distribution or record of the energies, velocities, masses, etc, of atoms, ions, electrons, etc: a mass spectrum|
|5.||any range or scale, as of capabilities, emotions, or moods|
|6.||another name for an afterimage|
|[C17: from Latin: appearance, image, from spectāre to observe, from specere to look at]|
spectrum spec·trum (spěk'trəm)
n. pl. spec·trums or spec·tra (-trə)
The distribution of a characteristic of a physical system or phenomenon, especially the distribution of energy emitted by a radiant source arranged in order of wavelengths.
The color image presented when white light is resolved into its constituent colors: red, orange, yellow, green, blue, indigo, violet.
The plot of intensity as opposed to wavelength of light emitted or absorbed by a substance, usually characteristic of the substance and used in qualitative and quantitative analysis.
The distribution of atomic or subatomic particles in a system, as in a magnetically resolved molecular beam, arranged in order of masses.
The group of pathogenic organisms against which an antibiotic or other antibacterial agent is effective.
spectrum [%PREMIUM_LINK%] (spěk'trəm) Pronunciation Key |
Plural spectra (spěk'trə) or spectrums