1. The soaking up of liquids by solids, or of gases by solids or liquids: Judy's mother used a special cloth to facilitate the absorption of the spilled milk.
2. The taking up of light or of its rays by black or colored rays: The absorption of the illumination by the black cloth seemed to be adequate.
3. The retention of radiant heat by the body, causing a rise in body temperature: Stanley was feeling quite hot which was caused by the absorption of the heat from the sun when he was at the beach.
4. The reduction in intensity of an X-ray photon as it passes through a substance or a beam of light as it passes through a solution which is used in clinical photometry as well as nuclear methods: At the laboratory the technicians were able to monitor the absorption of the electromagnetic energy as it passed through the blue solution.
5. The passage of a substance through some surface of the body into body fluids and tissues, such as the passage of ether through the respiratory epithelium of the lungs into the blood during anesthesia, or the passage of oil of wintergreen through the skin, which is the result of several processes like diffusion, filtration, and osmosis: Rodney, the anesthesiologist, frequently checked the level of absorption of the ether during the surgery.
6. The process by which a liquid or gas is drawn into the permeable pores of a solid material: The clean gauze bandage slowed the absorption of the blood from the wound.
7. In physiology, the passage of substances across and into tissues, such as the passage of digested food molecules into intestinal cells or the passage of liquid into kidney tubules: The various types of medical absorptions include agglutinin absorption, cutaneous absorption, external absorption, intestinal absorption, parenteral absorption, and pathological absorption.

A process in which sound energy is reduced as sonic waves strike or pass through a surface: The engineer worked to develop a plan for better acoustic absorption in the large auditorium.

1. The soaking up of radiation by the air and moisture in the mixture of gases surrounding the Earth's surface: In Howard's physics class, two of the students invented a gauge to measure atmospheric absorption.
2. The reduction of the energy of microwaves by the presence of moisture in the gases surrounding the Earth: The static in the skies at night in the local area appeared to cause the atmospheric absorption of the microwaves, which were interfering with the radar system.

1. The energy losses in a dielectric medium when the medium is exposed to a time-varying electric field.
2. The undesirable tendency of certain dielectrics to retain a portion of an electric charge after removal of the electric field.

The soaking up of a substance usually excreted: Pathological absorption refers to, for example, urine or a product of disease processes, such as pus, that is sucked up into the blood or lymph.