Arachnids are a diverse group of eight-legged arthropods that include spiders, scorpions, ticks, and mites. Synonyms for arachnids can vary depending on their specific classification, but they have a variety of different names in different contexts. For example, spiders might be referred to as araneids, while scorpions might be known as scorpionids. Ticks and mites might be grouped together as acarids or Acari. Other synonyms might include chelicerates, arthro-gastrulae, or even simply "spidery things." Regardless of their names, arachnids are fascinating creatures with unique adaptations and behaviors that make them important members of many ecosystems around the world.