#segment

• Actinomere — An anatomical segment or structural zone within a body exhibiting radial symmetry, corresponding to one of the repetitive sections arranged around the central axis. In invertebrate zoology, the term describes each of the similar radial segments making up the body of certain echinoderms (such as the arms of starfish) or coelenterates, including the internal organs and skeletal structures associated with that section.
• Annelid — An invertebrate animal from the phylum Annelida, structurally characterized by segmented rings (metamerism), with the body composed of a series of similar ring-like segments. As an adjective, it describes any organism, anatomical trait, or biological process displaying ringed or metameric structures.
• Annelids — A major phylum of bilaterally symmetrical invertebrate animals (Annelida), comprising segmented worms such as earthworms, leeches, and marine polychaetes. Structurally, their body is characterized by homonomous metamerism, being divided externally and internally (by transverse septa) into a series of repeating ring-like segments, possessing a closed circulatory system and a ventral ganglionic nerve cord.
• Anisomer — An asymmetric isomer or a compound substance formed by molecules whose segments or atomic groups do not present an equal ratio of geometric, structural, or molecular mass symmetry. As an adjective, it describes a state, chemical bond, or macromolecular process characterized by the inequality of components or polymeric segments, causing divergent physico-chemical properties.
• Anomomery — An anatomical phenomenon or structural characteristic found in some segmented animals (such as arthropods or annelids), consisting of the irregular variation, inequality, or asymmetry in the number or shape of segments (metameres) within homologous body regions. It represents a deviation from standard symmetrical metamerism, studied within invertebrate evolutionary morphology.
• Arches — The plural form of the neuter noun 'arc'; curved structural or decorative elements supported by two endpoints, used in architecture to span a space or support a vault or wall. In geometry, it represents continuous portions of curved lines, especially of circles, bounded by two distinct points. In music and engineering, it refers to springs acting as elastic mechanisms or bows used for stringed instruments.
• Areated — Exhibiting distinct areas, spaces, or structurally delimited zones; divided into specific surfaces or areas. In a rare technical or scientific sense, it can describe a body, a plant tissue, or a geometric profile marked by a clear zonal arrangement or which has undergone an area calculation, representing a rare literary derived form used to suggest precise spatial segmentation.
• Arthrocereus microsphaericus — The scientific name of a rare and endangered cactus species belonging to the Arthrocereus genus, found exclusively in the mountainous regions of eastern Brazil. The plant is structurally recognized by its very small globular or cylindrical segments (hence the name 'microsphaericus'), with reduced spines, forming compact clumps at soil level and bearing major ecological importance in biodiversity conservation.
• Archaic segments — An archaic plural form or obsolete technical variant designating detachable segments, nodes, or structural divisions of plant stalks, or minor joints of metal typefaces in early printing offices. It represents an early adaptation of scientific terms from the European space.
• Arthromere — An anatomical segment or primitive development zone within an embryonic limb, directly involved in the formation of future joints and adjacent skeletal structures. In evolutionary biology and morphology, the term describes a repetitive structural unit or metamere of the limbs, acting as a genetic organizing center that coordinates the proper alignment of bones and synovial capsules during organogenesis.
• Auxomery — A structural type or rare biological variation characterized by the unequal division or multiplication of chromosomal segments or metameric structures, leading to a macroscopic differentiation in the growth rate and enlargement of homologous organs of the same plant or living organism.