#gas

• Abd el-Krim — Moroccan military and political leader (1882-1963) during the Rif War; his forces and civilian populations were among the first historical targets of large-scale chemical warfare (mustard gas), making this a milestone case in military toxicology and long-term chemical weapon pathology.
• Abietin — A term used in early pharmaceutical chemistry to describe a bitter principle, resinous substance, or glycoside extracted from the bark and needles of certain conifer species (genus Abies). In past centuries, researchers analyzed abietin for its febrifuge (fever-reducing) and stimulant potential, but overdosing concentrated remedies containing this compound could cause acute gastric irritation or toxic nephritis.
• Abt Frantz — The traditional popular and pharmaceutical name (originating from the Germanic area as 'Abbe Franz') for a tonic gastric tincture or elixir, historically used as a stomachic remedy to stimulate digestion, combat flatulence, and soothe abdominal spasms. Its formula was based on hydroalcoholic extracts of bitter and aromatic herbs, being a common preparation in Transylvanian and Central European pharmacies until the mid-20th century.
• Lollipop — A delightful confectionery product, spherical, discoid, or spiraled in shape, made by boiling and solidifying granulated sugar or glucose syrup, enriched with various flavorings and food colorings. Its defining structural element is the rigid stick (made of wood, plastic, or pressed paper) on which it is fixed, designed to facilitate clean and prolonged consumption. Beyond its culinary role, the lollipop is a universal symbol of childhood, nostalgia, and pop culture, embedded in countless artistic expressions and festive traditions.
• Achalasia — A rare primary motor disorder of the esophagus, characterized by the absence of normal peristalsis in the esophageal body and the defective or incomplete relaxation of the lower esophageal sphincter during swallowing. This neurodegenerative condition leads to food accumulation in the esophagus, causing its progressive dilation, clinically manifesting as dysphagia (difficulty swallowing), regurgitation, retrosternal pain, and weight loss.
• Acteon — A current graphic and phonetic variant in the Romanian language for 'Actaeon'; a hero hunter in Greek mythology transformed into a stag by the goddess Artemis and torn apart by his own hounds. In an extended scientific sense, the name defines a genus of marine gastropod snails (Acteonidae) with delicate spiral shells, as well as a main-belt asteroid discovered in the 20th century, both borrowing the structural connotation of the mythological name.
• Acteonella — Romanian term (derived from the fossil genus Acteonella) for a type of prehistoric marine gastropod snails, characteristic of the Cretaceous period. Its structural shell is thick, oval or fusiform in shape, smooth, and provided with distinct columellar plications. Acteonella fossils are frequently used in geology as index fossils for dating sedimentary strata and reconstructing ancient equatorial marine environments.
• Actinon — A historical and scientific term used to designate the radioactive isotope radon-219 (An), a structural intermediate product within the natural decay chain of actinium or uranium-235. It is a heavy, unstable noble gas with an extremely short half-life of approximately 3.96 seconds, emitting high-energy alpha particles before transforming into polonium-215, monitored in nuclear research laboratories for the study of radioactive emanations.
• Adamsite — A toxic synthetic chemical substance belonging to the organic arsenical class, historically used as a riot control agent or irritating sneeze gas during World War I. Scientifically known as phenarsazine chloride, this crystalline compound causes severe respiratory tract irritation, violent sneezing, nausea, and headaches upon inhalation, currently classified as a chemical weapon banned by international treaties.
• Adelomorphous — Having an indefinite, vague, or poorly defined shape; in histology, it specifically refers to the chief (adelomorphous) gastric cells within the stomach glands, characterized by indistinct cell boundaries and a granular cytoplasm that secretes pepsinogen. This structural term describes microscopic entities whose morphological profile lacks a clear geometric differentiation relative to the surrounding tissues.
• Adenovirus — A genus of medium-sized, non-enveloped viruses with an icosahedral structure and a double-stranded DNA genome, responsible for a wide range of infectious diseases in humans and animals. This structural pathogen frequently infects the linings of the respiratory, digestive, and ocular tracts, causing rhinitis, pharyngitis, gastroenteritis, or epidemic conjunctivitis.
• Adiabatic — Occurring or taking place without exchange of heat with the external environment; a structural thermodynamic process or transformation in which the isolated physical system neither receives nor gives up thermal energy, the variation of internal energy being achieved exclusively through the mechanical work performed by or on the system.
• Air — The invisible, odorless, and tasteless gaseous mixture that makes up the Earth's atmosphere, structurally composed mainly of nitrogen (about 78%) and oxygen (about 21%), along with small amounts of argon, carbon dioxide, and other gases. Figuratively, the term describes an appearance, demeanor, a specific atmosphere of a place, or a gentle breeze of wind.
• Aerangis — A genus of tropical epiphytic and lithophytic orchids in the family Orchidaceae, native primarily to tropical Africa and Madagascar, structurally characterized by short stems, fleshy distichously arranged leaves, and pendulous inflorescences with star-shaped, white or translucent flowers that feature a long nectar spur and emit an intense fragrance during the night.
• Aërangis modesta — An elegant, medium-sized species of epiphytic orchid, endemic to Madagascar and the Comoro Islands. It is structurally characterized by glossy, obovate, bright-green leaves and spectacular pendulous spikes that can support up to 30 star-like, perfectly symmetrical white flowers, featuring short translucent spurs that emit a delicate, citrus-like fragrance during the night.
• Aeration — The natural or artificial process of air penetration and circulation inside a porous structure, soil, or liquid medium; the state of ventilation of a space. In geology and agronomy, it specifically refers to the gaseous exchange between the earth's atmosphere and soil pores, vital for the respiration of underground organisms.
• Aeriform — Having the form, properties, or appearance of air; a physical state of matter characterized by the lack of a definite shape and a fixed volume, showing a natural tendency for indefinite expansion. In modern scientific terminology, the term is used as a refined synonym for the gaseous state, describing substances whose molecules have high kinetic energy and minimal cohesion.
• Aerocoly — A digestive disorder manifested by the excessive accumulation of air or gas inside the colon, causing abdominal distension, flatulence, and colicky pain. This clinical phenomenon is often the result of aerophagia, increased bacterial fermentation, or intestinal motility disorders.
• Air embolism — A severe medical condition characterized by the entry and entrapment of air or gas bubbles inside the blood circulatory system, leading to the obstruction of blood vessels (ischemia) in vital tissues. This clinical phenomenon often occurs during invasive surgical procedures, severe traumas, or rapid decompression in divers or pilots.
• Aerophagia — A functional digestive disorder characterized by the involuntary and excessive swallowing of air during eating, speaking, or during periods of high anxiety, leading to gas buildup in the stomach, a feeling of fullness, frequent eructations, abdominal meteorism, and gastric discomfort.