#spider

• Acaricide — A chemical substance, biological preparation, or drug specifically designed to kill mites and ticks and to arrest the multiplication or development of their eggs and larvae. In phytopharmacy, it is deployed as a protective pesticide for crops against spider mites, whereas in human and veterinary medicine, it serves as a topical antiparasitic lotion to eradicate ectoparasites causing scabies or tick infestations.
• Aloe humilis — The scientific name of the dwarf aloe (or spider aloe), a small-sized species of succulent plant in the family Asphodelaceae, native to the Cape Province of South Africa. This structural ornamental plant forms dense, compact rosettes lacking an aerial stem, with triangular, erect-incurved bluish-green leaves completely covered on both sides with white tubercles and soft, fine spines, being highly popular as a houseplant due to its high resilience.
• Ammothea — A taxonomic genus comprising species of sea spiders (pycnogonids) belonging to the Ammotheidae family, predominantly distributed in the cold and deep waters of the world's oceans, including Antarctic regions. These marine invertebrates are structurally characterized by an extremely reduced body and unusually long legs relative to the trunk, possessing a well-developed proboscis used to absorb nutrients from the tissues of soft organisms, such as cnidarians or sea sponges.
• Anacampseros arachnoides — A species of small perennial succulent plant endemic to the Cape Provinces of South Africa, belonging to the family Anacampserotaceae. The plant forms compact rosettes of fleshy, ovate, dark-green or purplish leaves, remarkable for the presence of long, tangled white hairs growing from the leaf axils, resembling a spider's web, which structurally function to trap nightly dew and shade the epidermis.
• Anaxibia — A name borne by several female characters in Greek mythology (including the wife of Nestor or the sister of Agamemnon) and, in a modern sense, the structural name of a genus of spiders within the family Dictynidae. In a mythical context, it describes female figures of royal lineage, while in a biological sense, it defines small-sized arthropods with irregular webs.
• Arachne — A character from Greek mythology, a talented young weaver from Lydia who challenged the goddess Athena to a weaving contest; after demonstrating flawless mastery while depicting the infidelities of the gods, she was transformed by the offended goddess into a spider condemned to weave eternally. Culturally and scientifically, her name serves as the foundational eponym from which all arachnid terminology derives, symbolizing artistic pride driven to hubris and the fatal confrontation between mortals and the divine.
• Arachnid — An alternative spelling variant for arahnidă (arachnid); any arthropod invertebrate belonging to the class Arachnida, characterized by a body divided into two distinct regions (prosoma and opisthosoma), the lack of antennae and wings, the presence of chelicerae and pedipalps, and exactly four pairs of articulated walking legs. As an adjective, it describes any anatomical, biological, or behavioral trait pertaining to this massive group which includes spiders, scorpions, ticks, and harvestmen.
• Arachnids — An alternative spelling variant for arahnide (arachnids); a major class of terrestrial or aquatic chelicerate arthropods, characterized by a body segmented into a cephalothorax and abdomen, the lack of antennae, the presence of two pairs of mouth appendages (chelicerae and pedipalps), and exactly eight articulated legs. The class includes spiders, scorpions, harvestmen, mites, and ticks, playing a vital ecological role as insect predators.
• Aragna — An archaic or regional spelling and phonetic variant derived directly from the Latin and Greek etymological roots for spider, encountered in medieval manuscripts, old translations, or as an isolated minor toponym in Mediterranean Europe. In Romanian historical linguistics and related dialects, the term marks the phonetic transition stages prior to the stabilization of words in the arachnid family.
• Arachn- — A scientific combining form (prefixoid) derived from ancient Greek, utilized in international scientific terminology to build new words directly related to spiders, arachnids, or reticular structures resembling a spiderweb. In the Romanian language, it is found adapted as 'arahn-' or 'arahno-' in medical or zoological compounds.
• Arachne — A famous character from Greek mythology, a young mortal woman from Lydia renowned for her exceptional mastery in the art of weaving; due to her hubris, she challenged the goddess Athena to a contest and, although her work was flawless, she was transformed by the offended divinity into a spider. Her name represents the eponym from which the entire biological classification of arachnids was formed, symbolizing the tragic conflict between human condition and divine authority.
• Arachnophobia — A persistent, abnormal, and unwarranted fear of spiders or other arachnids, representing one of the most common specific animal phobias experienced by humans worldwide. This anxiety disorder triggers extreme emotional and physiological reactions, such as panic attacks, heavy sweating, and severe avoidance behaviors, even at the mere sight of a picture or the anticipation of a spider's presence.
• Arachnid — Any arthropod invertebrate belonging to the class Arachnida, characterized by a body divided into two distinct regions named cephalothorax (prosoma) and abdomen (opisthosoma), the total lack of antennae and wings, the presence of chelicerae and pedipalps as mouth appendages, and exactly eight articulated legs destined for terrestrial locomotion. As an adjective, it describes any structural, biological, or behavioral trait specific to this vast group including spiders, scorpions, ticks, and harvestmen.
• Arachnid — Any arthropod invertebrate belonging to the class Arachnida, characterized by a body divided into two distinct regions, the cephalothorax and abdomen, the total lack of antennae and wings, the presence of chelicerae and pedipalps, and exactly eight articulated walking legs. The term defines both scientifically and popularly the members of a vast and adaptable group of terrestrial predators or parasites, including spiders, scorpions, mites, and ticks.
• Arachno- — A scientific combining form (prefixoid) of Greek origin, utilized in international scientific terminology to construct compound words referring to spiders, the arachnid class, or fine structures with a reticular appearance resembling a spiderweb. In the Romanian language, it serves as a foundation for numerous neologisms within zoology, psychiatry, or neuroanatomy, such as arahnologie, arahnofobie, or arahnoidită.
• Arachnodactyly — A congenital anomaly characterized by the excessive length, slenderness, and unusual flexibility of the fingers and toes, causing them to assume an elongated appearance reminiscent of a spider's legs. It represents a major clinical sign and a foundational diagnostic criterion for hereditary connective tissue disorders, most frequently associated with Marfan syndrome or Loeys-Dietz syndrome.
• Arachnophobia — A pathological, intense, persistent, and irrational fear of spiders or other arachnids, representing one of the most widespread specific animal phobias identified in the human species. This anxiety disorder dictates severe neurovegetative reactions, such as immediate panic attacks, palpitations, and an uncontrollable urge to escape, triggered not only by physical contact but also by images, simulations, or the mere anticipation of a spider's presence.
• Arachnoid — Resembling a spider web in fineness, structure, or network of filaments; arachnoidal. In human and animal anatomy, the term describes delicate meningeal elements or membranes, whereas in zoology it is rarely used as a noun to denote a member of the arachnid class or a morphological feature reminiscent of the order of spiders.
• Arachnologist — A scholar or specialist in arachnology; a biologist dedicated to the methodical and scientific study of organisms within the class Arachnida, including spiders, scorpions, harvestmen, and mites. This specialist investigates the taxonomy, evolutionary anatomy, behavioral ecology, and biochemical composition of these invertebrate arthropods' venoms, playing an important role in monitoring global biodiversity.
• Arachnologist — A woman who specializes in arachnology; a female biologist or zoologist dedicated to the scientific and methodical study of organisms within the class Arachnida, such as spiders, scorpions, mites, and harvestmen. Her activity encompasses field work for collecting specimens, laboratory taxonomic analysis, describing new species, and studying the ecological or biochemical impact of these invertebrates venoms.