\Pneu*mat"ic\, n.
A vehicle, as a bicycle, the wheels of which are fitted with
pneumatic tires.

\Pneu*mat"ic\, Pneumatical \Pneu*mat"ic*al\, a.
Adapted for containing compressed air; inflated with air; as,
a pneumatic cushion; a pneumatic tire, a tire formed of an
annular tube of flexible fabric, as India rubber, suitable
for being inflated with air.

\Pneu*mat"ic\, Pneumatical \Pneu*mat"ic*al\, a. [L.
pneumaticus, Gr. ?, fr. ?, ?, wind, air, ? to blow, breathe;
cf. OHG. fnehan: cf. F. pneumatique. Cf. {Pneumonia}.]
1. Consisting of, or resembling, air; having the properties
   of an elastic fluid; gaseous; opposed to dense or solid.
         The pneumatical substance being, in some bodies, the
         native spirit of the body.            --Bacon.
2. Of or pertaining to air, or to elastic fluids or their
   properties; pertaining to pneumatics; as, pneumatic
   experiments. ``Pneumatical discoveries.'' --Stewart.
3. Moved or worked by pressure or flow of air; as, a
   pneumatic instrument; a pneumatic engine.
4. (Biol.) Fitted to contain air; Having cavities filled with
   air; as, pneumatic cells; pneumatic bones.
{Pneumatic action}, or {Pneumatic lever} (Mus.), a
   contrivance for overcoming the resistance of the keys and
   other movable parts in an organ, by causing compressed air
   from the wind chest to move them.
{Pneumatic dispatch}, a system of tubes, leading to various
   points, through which letters, packages, etc., are sent,
   by the flow and pressure of air.
{Pneumatic elevator}, a hoisting machine worked by compressed
   air.
{Pneumatic pile}, a tubular pile or cylinder of large
   diameter sunk by atmospheric pressure.
{Pneumatic pump}, an air-exhausting or forcing pump.
{Pneumatic railway}. See {Atmospheric railway}, under
   {Atmospheric}.
{Pneumatic syringe}, a stout tube closed at one end, and
   provided with a piston, for showing that the heat produced
   by compressing a gas will ignite substances.
{Pneumatic trough}, a trough, generally made of wood or sheet
   metal, having a perforated shelf, and used, when filled
   with water or mercury, for collecting gases in chemical
   operations.
{Pneumatic tube}. See {Pneumatic dispatch}, above.