Pleurite

Part of speech: noun

Definitions

1. A hardened plate or segment forming part of the outer body wall of an arthropod, such as one of the rings of a crab's shell
2. One of the sclerotized sections that make up the external skeleton of an insect or crustacean body
3. A jointed plate of the exoskeleton in arthropods, lying between the segments of the body wall and providing protection

Etymology: Greek "pleura" meant "rib" or "side of the body," and an anatomist working from that root would have had little trouble naming the plates along the sides of an animal. The body of an insect or crustacean is built from a series of segments, each with hard plates on its back, belly, and flanks. The side plates are the pleurites, so the word describes a specific piece of anatomy rather than an everyday object. The ending "-ite" here does not mean "mineral," as it does in "graphite." In anatomical terms it means "part of" or "belonging to," so a pleurite is simply a piece of the pleura, the side region. It sits in a family of matching terms: "tergite" for the back plate and "sternite" for the belly plate, all built on the same pattern. These are modern scientific coinages from Greek roots, not words the ancient Greeks used for insect parts.