1. [n]  travel via aircraft; "air travel involves too much waiting in airports"; "if you've time to spare go by air"
2. [n]  a distinctive but intangible quality surrounding a person or thing; "an air of mystery"; "the house had a neglected air"; "an atmosphere of defeat pervaded the candidate's headquarters"; "the place had an aura of romance"
3. [n]  medium for radio and television broadcasting; "the program was on the air from 9 til midnight"; "the president used the airwaves to take his message to the people"
4. [n]  a succession of notes forming a distinctive sequence; "she was humming an air from Beethoven"
5. [n]  the region above the ground; "her hand stopped in mid air"; "he threw the ball into the air"
6. [n]  a slight wind (usually refreshing); "the breeze was cooled by the lake"; "as he waited he could feel the air on his neck"
7. [n]  a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of; "air pollution"; "a smell of chemicals in the air"; "open a window and let in some air"; "I need some fresh air"
8. [n]  (archaic) once thought to be one of four elements composing the universe (Empedocles)
9. [v]  expose to cool or cold air so as to cool or freshen; "air the old winter clothes"; "air out the smoke-filled rooms"
10. [v]  expose to warm or heated air, so as to dry; "Air linen"
11. [v]  make public; "She aired her opinions on welfare"
12. [v]  broadcast over the airwaves, as in radio or television; "We cannot air this X-rated song"
13. [v]  be broadcast; "This show will air Saturdays at 2 P.M."
14. [v]  expose to fresh air, as of old clothing; "aerate your old sneakers"

Air
Uses simple experiments to demonstrate the properties of air including air pressure and expansion, how flight is achieved, and how rust is produced.

more details ...

1. \Air\ ([^a]r), n. [OE. air, eir, F. air, L. a["e]r, fr. Gr.
   'ah`r, air, mist, for 'a[digamma]hr, fr. root 'a[digamma] to
   blow, breathe, probably akin to E. wind. In sense 10 the
   French has taking a meaning fr. It. aria atmosphere, air, fr.
   the same Latin word; and in senses 11, 12, 13 the French
   meaning is either fr. L. aria, or due to confusion with F.
   aire, in an older sense of origin, descent. Cf. {A["e]ry},
   {Debonair}, {Malaria}, {Wind}.]
   1. The fluid which we breathe, and which surrounds the earth;
      the atmosphere. It is invisible, inodorous, insipid,
      transparent, compressible, elastic, and ponderable.
   Note: By the ancient philosophers, air was regarded as an
         element; but modern science has shown that it is
         essentially a mixture of oxygen and nitrogen, with a
         small amount of carbon dioxide, the average proportions
         being, by volume: oxygen, 20.96 per cent.; nitrogen,
         79.00 per cent.; carbon dioxide, 0.04 per cent. These
         proportions are subject to a very slight variability.
         Air also always contains some vapor of water.
   2. Symbolically: Something unsubstantial, light, or volatile.
      ``Charm ache with air.'' --Shak.
            He was still all air and fire. [Air and fire being
      the finer and quicker elements as opposed to earth and
      water.]                                     --Macaulay
      .
   3. A particular state of the atmosphere, as respects heat,
      cold, moisture, etc., or as affecting the sensations; as,
      a smoky air, a damp air, the morning air, etc.
   4. Any a["e]riform body; a gas; as, oxygen was formerly
      called vital air. [Obs.]
   5. Air in motion; a light breeze; a gentle wind.
            Let vernal airs through trembling osiers play.
                                                  --Pope.
   6. Odoriferous or contaminated air.
   7. That which surrounds and influences.
            The keen, the wholesome air of poverty.
                                                  --Wordsworth.
   8. Utterance abroad; publicity; vent.
            You gave it air before me.            --Dryden.
   9. Intelligence; information. [Obs.] --Bacon.
   10. (Mus.)
       (a) A musical idea, or motive, rhythmically developed in
           consecutive single tones, so as to form a symmetrical
           and balanced whole, which may be sung by a single
           voice to the stanzas of a hymn or song, or even to
           plain prose, or played upon an instrument; a melody;
           a tune; an aria.
       (b) In harmonized chorals, psalmody, part songs, etc.,
           the part which bears the tune or melody -- in modern
           harmony usually the upper part -- is sometimes called
           the air.
   11. The peculiar look, appearance, and bearing of a person;
       mien; demeanor; as, the air of a youth; a heavy air; a
       lofty air. ``His very air.'' --Shak.
   12. Peculiar appearance; apparent character; semblance;
       manner; style.
             It was communicated with the air of a secret.
                                                  --Pope.
   12. pl. An artificial or affected manner; show of pride or
       vanity; haughtiness; as, it is said of a person, he puts
       on airs. --Thackeray.
   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.
   

2. \Air\ ([^a]r), v. t. [imp. & p. p. {Aired} ([^a]rd); p. pr.
   & vb. n. {Airing}.] [See {Air}, n., and cf. {A[eum]rate}.]
   1. To expose to the air for the purpose of cooling,
      refreshing, or purifying; to ventilate; as, to air a room.
            It were good wisdom . . . that the jail were aired.
                                                  --Bacon.
            Were you but riding forth to air yourself. --Shak.
   2. To expose for the sake of public notice; to display
      ostentatiously; as, to air one's opinion.
            Airing a snowy hand and signet gem.   --Tennyson.
   3. To expose to heat, for the purpose of expelling dampness,
      or of warming; as, to air linen; to air liquors.
   

A future infrared standard from IrDA. AIR will provide in-room multipoint to multipoint connectivity. AIR supports a data rate of 4 Mbps at a distance of 4 metres, and 250 Kbps at up to 8 metres. It is designed for cordless connections to multiple peripherals and meeting room collaboration applications.

See also IrDA Data and IrDA Control

the atmosphere, as opposed to the higher regions of the sky (1 Thess. 4:17; Rev. 9:2; 16:17). This word occurs once as the rendering of the Hebrew _ruah_ (Job 41:16); elsewhere it is the rendering of _shamaiyim_, usually translated "heavens."

The expression "to speak into the air" (1 Cor. 14:9) is a proverb denoting to speak in vain, as to "beat the air" (1 Cor. 9:26) denotes to labour in vain.