Of or pertaining to air, or gases in general, or their properties; also, employing (compressed) air or other gas as a motive power, as, pneumatic experiments; a pneumatic engine.Consisting of or resembling air; having the properties of an elastic fluid; gaseous.Moved or played by means of air: as, a pneumatic instrument of music.In zoology: Filled with air; fitted to receive or contain air; pneumatized, as the air-cells or the bones of birdsOf or pertaining to the respiratory system of any animalA caisson within which compressed air excludes the water, permitting necessary operations to be carried on inside it.n. In organ-building, one of the members of a pneumatic action, whether a bellows or a tube. See pneumatic action, above.n. Same as pneumatology, 2, where see quotation.In theology, relating to the spirit or pneuma, as distinguished from both soul and body; spiritual. See soul and spirit.n. An inflatable rubber tire.n. A vehicle, as a bicycle, motor-cycle, or motorcar, lifted with inflatable rubber tires.