operated by or containing gas or air under pressure or by a vacuum
relating to air, gas, or wind
said of a machine or tool: operated by gas or air under pressure or by a vacuum
containing air under pressure
a pneumatic tyre
said of the bones of birds: having air-filled cavities, an adaptation which makes them lighter in flight
pneumatically adv
pneumaticity /-ʹtisiti/ noun
[via Latin from Greek pneumatikos, from pneuma air, breath, spirit]