absolute humidity See humidity
absorbed dose The amount of energy absorbed by a tissue or other substance from incident radiation. It is measured in grays Gy one gray the transfer of one joule of energy to one kilogram of material. absorption 1. The retention of radiant energy by an object, e.g. by the pigments of a photosynthetic organism. 2. The uptake of small nutrient molecules into the body of an organism. In animals this takes place after digestion of larger food molecules. In plants it includes the uptake of water and...