Of or pertaining to a pleura or the pleuræ as, the pleural investment of the lungs; the pleural cavity; pleural effusion or adhesions. Also pleuric.Pertaining to a rib or a pleuron, or to the ribs or the pleura collectively; costal; situated on the side of the thorax or chest.Lateral, in general; situated on the side of the body: correlated with dorsal, ventral, etc.In arthropods, pertaining to an arthropleura or pleurite: applied to the lateral limb-bearing section of an arthromere, between the sternite and the tergite. See cuts under Brachyura and Trilobita.Especially, in entomology, lateral and thoracic: as, a pleural sclerite; a pleural segment of a thoracic somite.n. A pleural process. Specifically: One of the bones that in turtles overlie and unite with the ribs, forming the greater portion of the carapace; a costal: correlative with neural. Most commonly used in the plural.n. In fishes, one of the long rays of bone attached to the side of the vertebras and extending downward partly around the abdominal cavity; a rib.