Webster's Revised Unabridged Dictionary · 1913

Pleura

Pleura , noun

plural of Pleuron.

Pleura (#) , noun

[New Latin, n. fem., from Greek {not transcribed} a rib, the side.]

1.
(a) (Anatomy) The smooth serous membrane which closely covers the lungs and the adjacent surfaces of the thorax; the pleural membrane.
(b)
(Anatomy) The closed sac formed by the pleural membrane about each lung, or the fold of membrane connecting each lung with the body wall.
2.
(Zoology) Same as Pleuron.