Definitions for absorbanceæbˈsɔr bəns, -ˈzɔr-
Random House Webster's College Dictionary
ab•sorb•ance*æbˈsɔr bəns, -ˈzɔr-(n.)
the capacity of a substance to absorb radiation.
Origin of absorbance:
A logarithmic measure of the amount of light that is absorbed when passing through a substance.