Also found in: Acronyms.
equivalent widthA measure of the strength of a spectral line. The line profile of an absorption line, for example, shows a dip below the continuum level, and the equivalent width is calculated as the area of the dip divided by the height of the continuum. It is the wavelength range of the spectral line if the amount of absorption was redistributed into a rectangle having the intensity of the continuum.
equivalent width[i′kwiv·ə·lənt ′width]
A measure of the total absorption of radiant energy as indicated by an absorption line or absorption band.