Absorption may refer to: Chemistry and biology Absorption (biology), digestion Absorption (small intestine) Absorption (chemistry), diffusion of particles of gas or liquid into liquid or solid materials Absorption (skin), a route by which substances enter the body through the skin Absorption (pharmacology), absorption of drugs into the body Physics and chemical engineering Absorption (acoustics), absorption of sound waves by a material Absorption (electromagnetic radiation), absorption of light or other electromagnetic radiation by a material Absorption air conditioning, a type of solar air conditioning Absorption refrigerator, a refrigerator that runs on surplus heat rather than electricity Dielectric absorption, the inability of a charged capacitor to completely discharge when briefly discharged Mathematics and economics Absorption (economics), the total demand of an economy for goods and services both from within and without Absorption (logic), one of the rules of inference Absorption costing, or total absorption costing, a method for appraising or valuing a firm's total inventory by including all the manufacturing costs incurred to produce those goods Absorbing element, in mathematics, an element that does not change when it is combined in a binary operation with some other element Absorption law, in mathematics, an identity linking a pair of binary operations See also Adsorption, the formation of a gas or liquid film on a solid surface CO2 scrubber, device which absorbs carbon dioxide from circulated gas Digestion, the uptake of substances by the gastrointestinal tract Absorption (psychology), a state of becoming absorbed by mental imagery or fantasy Flow (psychology), a state of total mental "absorption"