noun. The ratio of absorbed to incident radiation.

noun. a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber

"Certainly, over the tropical midday deep oceans, the ocean absorptance must be in teh range of 97-98%, since the near normal incident radiation simply goes on down till something absorbs it."

absorbance  absorbancy  

coefficient  

birthrate  calorimeter  centrifugation  centroid  congealing