Question

What is a spectrum? Please give the complete definition.

Answer 1

Ok.. Guys i m giving the definition of spectrum:
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism... Thank you.
Hope this helps

Answer 2

the light rays emits from any object.
ex. the 
1.a band of colours, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.2.used to classify something in terms of its position on a scale between two extreme points."the left or the right of the political spectrum"