Source : Webster's Revised Unabridged Dictionary (1913)

   14. (Paint.)
       (a) The representation or reproduction of the effect of
           the atmospheric medium through which every object in
           nature is viewed. --New Am. Cyc.
       (b) Carriage; attitude; action; movement; as, the head of
           that portrait has a good air. --Fairholt.

   15. (Man.) The artificial motion or carriage of a horse.

   Note: Air is much used adjectively or as the first part of a
         compound term. In most cases it might be written
         indifferently, as a separate limiting word, or as the
         first element of the compound term, with or without the
         hyphen; as, air bladder, air-bladder, or airbladder;
         air cell, air-cell, or aircell; air-pump, or airpump.

   {Air balloon}. See {Balloon}.

   {Air bath}.
       (a) An apparatus for the application of air to the body.
       (b) An arrangement for drying substances in air of any
           desired temperature.

   {Air castle}. See {Castle in the air}, under {Castle}.

   {Air compressor}, a machine for compressing air to be used as
      a motive power.

   {Air crossing}, a passage for air in a mine.

   {Air cushion}, an air-tight cushion which can be inflated;
      also, a device for arresting motion without shock by
      confined air.

   {Air fountain}, a contrivance for producing a jet of water by
      the force of compressed air.

   {Air furnace}, a furnace which depends on a natural draft and
      not on blast.

   {Air line}, a straight line; a bee line. Hence

   {Air-line}, adj.; as, air-line road.

   {Air lock} (Hydr. Engin.), an intermediate chamber between
      the outer air and the compressed-air chamber of a
      pneumatic caisson. --Knight.

   {Air port} (Nav.), a scuttle or porthole in a ship to admit
      air.

   {Air spring}, a spring in which the elasticity of air is
      utilized.

   {Air thermometer}, a form of thermometer in which the
      contraction and expansion of air is made to measure
      changes of temperature.

   {Air threads}, gossamer.

   {Air trap}, a contrivance for shutting off foul air or gas
      from drains, sewers, etc.; a stench trap.

   {Air trunk}, a pipe or shaft for conducting foul or heated
      air from a room.

   {Air valve}, a valve to regulate the admission or egress of
      air; esp. a valve which opens inwardly in a steam boiler
      and allows air to enter.

   {Air way}, a passage for a current of air; as the air way of
      an air pump; an air way in a mine.

   {In the air}.
       (a) Prevalent without traceable origin or authority, as
           rumors.
       (b) Not in a fixed or stable position; unsettled.
       (c) (Mil.) Unsupported and liable to be turned or taken
           in flank; as, the army had its wing in the air.

   {To take air}, to be divulged; to be made public.

   {To take the air}, to go abroad; to walk or ride out.

Fountain \Foun"tain\ (foun"t[i^]n), n. [F. fontaine, LL.
   fontana, fr. L. fons, fontis. See 2d {Fount}.]
   1. A spring of water issuing from the earth.

   2. An artificially produced jet or stream of water; also, the
      structure or works in which such a jet or stream rises or
      flows; a basin built and constantly supplied with pure
      water for drinking and other useful purposes, or for
      ornament.

   3. A reservoir or chamber to contain a liquid which can be
      conducted or drawn off as needed for use; as, the ink
      fountain in a printing press, etc.

   4. The source from which anything proceeds, or from which
      anything is supplied continuously; origin; source.

            Judea, the fountain of the gospel.    --Fuller.

            Author of all being, Fountain of light, thyself
            invisible.                            --Milton.

   {Air fountain}. See under {Air}.

   {Fountain heead}, primary source; original; first principle.
      --Young.

   {Fountain inkstand}, an inkstand having a continual supply of
      ink, as from elevated reservoir.

   {Fountain lamp}, a lamp fed with oil from an elevated
      reservoir.

   {Fountain pen}, a pen with a reservoir in the handle which
      furnishes a supply of ink.

   {Fountain pump}.
      (a) A structure for a fountain, having the form of a pump.
      (b) A portable garden pump which throws a jet, for
          watering plants, etc.

   {Fountain shell} (Zo["o]l.), the large West Indian conch
      shell ({Strombus gigas}).

   {Fountain of youth}, a mythical fountain whose waters were
      fabled to have the property of renewing youth.