Pleura

n. pl. L. Pleuræ (#), E. Pleuras (#).
  1. (Anat.) Same as Pleuron.
    1. The smooth serous membrane which closely covers the lungs and the adjacent surfaces of the thorax; the pleural membrane.
    2. The closed sac formed by the pleural membrane about each lung, or the fold of membrane connecting each lung with the body wall.