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 device, used in measuring gases, that absorbs a gas or some constituent from a mixture and estimates the quantity either from properties of the absorbed material or from the reduced residual volume remaining after absorption: "Mr. Dillman studied the operations manual of the absorption apparatus for three days before he conceded defeat."

A large pit used to absorb effluent from a septic tank; usually, filled with coarse aggregate arranged within a distribution system.

A device that transfers thermal energy from a heat source to a heat sink through an absorbent fluid and a refrigerant.

Most commercial absorption chillers use lithium bromide (a salt) and water as the fluid pair, with lithium bromide being the absorbent and water the refrigerant.

A measure of the amount of incident energy that is absorbed per unit distance or unit mass of a substance.

A process within a refrigeration system during which the primary fluid (the refrigerant) and the secondary fluid (the absorbent) mix after the refrigerant leaves the evaporator.

A variation in the absorption of radio waves propagated through the ionosphere due to changes in the densities of ionization.

A system of trenches filled with coarse aggregate surrounding distribution pipes; used to seep septic tank effluent into the surrounding soil.

An apparatus used to measure atmospheric humidity, using a drying agent to absorb and then to weigh the amount of water vapor in a known quantity of air.

In optics, a lens often used in eyeglasses, designed to absorb certain wavelengths in order to inhibit their passage through the lens.

An instrument used to measure the amount of light transmitted through a transparent liquid or solid by means of a photocell or other light detector.

In acoustical engineering, a type of amplitude modulation that couples a variable-impedance device; such as, a microphone, to the output stage of a radio transmitter.

Energy is thus absorbed from the transmitter according to the information captured by the microphone.

In building engineering, the amount of water absorbed by a brick or other porous building material, expressed in grams or ounces per minute.

A technique for determining the concentration and structure of a substance, by measuring the amount of electromagnetic radiation that the sample absorbs at various wavelengths.

Spectrum of absorption lines produced when light passes through and is partially absorbed by a substance.

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.

A large increase of electric and radio wave density in the D-level of the atmosphere caused by electron-bombardment of the atmosphere during an aurora or a geomagnetic storm.

The normal absorption of water (important in the conservation of body fluids) and products of bacterial action; especially, in the ascending colon.

Some nutrients and drugs are absorbed by the lower bowel. In humans, cellulose is not digested or absorbed but passes from the body as unchanged residue.

Absorption through the skin.

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.

Any spectrum produced by the absorption of electromagnetic radiation by ions, atoms, or molecules as a result of electron excitation.

Absorption of material by the skin and the mucous membrane.

A penetration-type thickness gage that measures the thickness or density of a sample by measuring its absorption of gamma rays.

Oral absorption of material.

Some substances, but no nutrients, can be absorbed from the mouth; some drugs; especially, alkaloids, can be absorbed through the oral mucosa.

Absorption from a site other than the gastrointestinal tract.

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.

In the digestive process, hydrolyzation of proteins to their constituent amino acids in the walls of the intestines.

They are transported via the portal vein to the liver and then into the general circulation and to the tissues.

Each tissue synthesizes its own form of protein from the amino acids received from the blood.

Absorption of digestive products that occurs in the small intestine; especially, the ileum.

Products of digestion absorbed from the gastrointestinal tract pass into either blood or lymph. The mesenteric veins unite to form the portal vein and to carry such blood to the liver, the mesenteric lymphatics are called lacteals because, during absorption of a fatty meal, the lymph they contain, called chyle, looks milky.

Absorption of water, alcohol, and some salts through the gastric mucosa.

The photometric measurement of the wavelengths of observable radiation taken in by a sample and which correspond to electron transitions from the ground state to an excited state: Professor Jess Monroe developed a new visible absorption spectrophotometry device that enhanced the scientific studies in his university classes.

In the teacher's advanced physics program, his students studied the visible absorptions spectrophotometries of light energy.