pleura

noun

pleu·​ra ˈplu̇r-ə How to pronounce pleura (audio)
plural pleurae ˈplu̇r-ˌē How to pronounce pleura (audio)
-ˌī
or pleuras
: the delicate serous membrane that lines each half of the thorax of mammals and is folded back over the surface of the lung of the same side
pleural adjective

Word History

Etymology

Middle English, from Medieval Latin, from Greek, rib, side

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of pleura was in the 15th century

Browse Nearby Words

Cite this Entry

“Pleura.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pleura. Accessed 10 Sep. 2025.

Kids Definition

pleura

noun
pleu·​ra ˈplu̇r-ə How to pronounce pleura (audio)
plural pleurae ˈplu̇(ə)r-ˌē How to pronounce pleura (audio)
-ˌī
or pleuras
: the delicate membrane lining each half of the chest of mammals and folded back over the surface of the lung of the same side
pleural adjective

Medical Definition

pleura

noun
pleu·​ra ˈplu̇r-ə How to pronounce pleura (audio)
plural pleurae ˈplu̇r-ē How to pronounce pleura (audio) or pleuras
: either of a pair of two-walled sacs of serous membrane each of which lines one lateral half of the thorax, has an inner visceral layer closely adherent to the corresponding lung, is reflected at the root of the lung to form a parietal layer that adheres to the walls of the thorax, the pericardium, the upper surface of the diaphragm, and adjacent parts, and contains a small amount of serous fluid that minimizes the friction of respiratory movements

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