1. The taking up of liquids by solids, or of gases by solids or liquids: "The housewife 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 light by the black cloth seemed to be adequate."
3. The taking up by the body of radiant heat, causing a rise in body temperature: "Stanley's higher temperature 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 (used in clinical photometry as well as nuclear methods): "At the laboratory they 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: diffusion, filtration, and osmosis): "The anaesthesiologist 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."