plural of PN

(medicine) A disease of the lungs caused by inhalation of particulate matter.

Of, relating to, or resembling air or other gases / Of or relating to pneumatics / Powered by, or filled with, compressed air / (zoology) Having cavities filled with air

(dated) A vehicle, such as a bicycle, whose wheels are fitted with pneumatic tyres.

(medicine) Pneumonia affecting one lung.

Pneumonia affecting both lungs.

An acute or chronic inflammation of the lungs caused by viruses, bacteria or other microorganisms, or sometimes by physical or chemical irritants.

(music) A neume. / The spirit or soul. / (Gnosticism) One of three levels of a human being, the spirit, along with the body and soul.

The system on military aircraft that use either or some combination of both hydraulic and pneumatic systems. / The science of fluids made of both gas and liquid.

Any device which generates or is powered by compressed air