an arthropod such as a spider, mite, tick, or scorpion, having a body that has two segments, the front segment bearing four pairs of legs
any of a class of arthropods including the spiders, mites, ticks, and scorpions, with bodies that have two segments, the front segment bearing four pairs of legs: class Arachnida
arachnid adj
[scientific Latin Arachnida, name of class, from Greek arachnē spider]