Definition of lung
1a
: one of the usually paired compound saccular thoracic organs that constitute the basic respiratory organs of an air-breathing vertebrate
b
: any of various respiratory organs of invertebrates
2a
: a device enabling individuals abandoning a submarine to rise to the surface
b
: a mechanical device for regularly introducing fresh air into and withdrawing stale air from the lung : respirator — compare iron lung
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Merriam-Webster unabridged
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Time Traveler for lung
The first known use of lung was before the 12th century
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