The Collaborative International Dictionary of English v.0.48:

Air \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.
      [1913 Webster]

   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.
         [1913 Webster]

   2. Symbolically: Something unsubstantial, light, or volatile.
      "Charm ache with air." --Shak.
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            He was still all air and fire. [Air and fire being
      the finer and quicker elements as opposed to earth and
      water.]                                     --Macaulay
      .
      [1913 Webster]

   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.
      [1913 Webster]

   4. Any a["e]riform body; a gas; as, oxygen was formerly
      called vital air. [Obs.]
      [1913 Webster]

   5. Air in motion; a light breeze; a gentle wind.
      [1913 Webster]

            Let vernal airs through trembling osiers play.
                                                  --Pope.
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   6. Odoriferous or contaminated air.
      [1913 Webster]

   7. That which surrounds and influences.
      [1913 Webster]

            The keen, the wholesome air of poverty.
                                                  --Wordsworth.
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   8. Utterance abroad; publicity; vent.
      [1913 Webster]

            You gave it air before me.            --Dryden.
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   9. Intelligence; information. [Obs.] --Bacon.
      [1913 Webster]

   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.
           [1913 Webster]

   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.
       [1913 Webster]

   12. Peculiar appearance; apparent character; semblance;
       manner; style.
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             It was communicated with the air of a secret.
                                                  --Pope.
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   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.
       [1913 Webster]

   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.
           [1913 Webster]

   15. (Man.) The artificial motion or carriage of a horse.
       [1913 Webster]

   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.
         [1913 Webster]

   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.

   on the air, currently transmitting; live; -- used of radio
      and television broadcasts, to indicate that the images and
      sounds being picked up by cameras and microphones are
      being broadcast at the present moment.

   Note: In call-in programs where individuals outside a radio
         or television studio have telephoned into the station,
         when their voice is being directly broadcast, the host
         of the program commonly states "You're on the air." as
         a warning that the conversation is not private.

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

   To take the air, to go abroad; to walk or ride out.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Air \Air\ ([^a]r), v. t. [imp. & p. p. Aired ([^a]rd); p. pr.
   & vb. n. Airing.] [See Air, n., and cf. A["e]rate.]
   1. To expose to the air for the purpose of cooling,
      refreshing, or purifying; to ventilate; as, to air a room.
      [1913 Webster]

            It were good wisdom . . . that the jail were aired.
                                                  --Bacon.
      [1913 Webster]

            Were you but riding forth to air yourself. --Shak.
      [1913 Webster]

   2. To expose for the sake of public notice; to display
      ostentatiously; as, to air one's opinion.
      [1913 Webster]

            Airing a snowy hand and signet gem.   --Tennyson.
      [1913 Webster]

   3. To expose to heat, for the purpose of expelling dampness,
      or of warming; as, to air linen; to air liquors.
      [1913 Webster]

WordNet (r) 3.0 (2006):

air
    n 1: 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"
    2: the region above the ground; "her hand stopped in mid air";
       "he threw the ball into the air"
    3: 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" [syn:
       air, aura, atmosphere]
    4: a slight wind (usually refreshing); "the breeze was cooled by
       the lake"; "as he waited he could feel the air on his neck"
       [syn: breeze, zephyr, gentle wind, air]
    5: the mass of air surrounding the Earth; "there was great heat
       as the comet entered the atmosphere"; "it was exposed to the
       air" [syn: atmosphere, air]
    6: once thought to be one of four elements composing the
       universe (Empedocles)
    7: a succession of notes forming a distinctive sequence; "she
       was humming an air from Beethoven" [syn: tune, melody,
       air, strain, melodic line, line, melodic phrase]
    8: 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" [syn: air,
       airwave]
    9: travel via aircraft; "air travel involves too much waiting in
       airports"; "if you've time to spare go by air" [syn: air
       travel, aviation, air]
    v 1: expose to fresh air; "aerate your old sneakers" [syn: air
         out, air, aerate]
    2: be broadcast; "This show will air Saturdays at 2 P.M."
    3: broadcast over the airwaves, as in radio or television; "We
       cannot air this X-rated song" [syn: air, send,
       broadcast, beam, transmit]
    4: make public; "She aired her opinions on welfare" [syn:
       publicize, publicise, air, bare]
    5: expose to warm or heated air, so as to dry; "Air linen"
    6: expose to cool or cold air so as to cool or freshen; "air the
       old winter clothes"; "air out the smoke-filled rooms" [syn:
       vent, ventilate, air out, air]

Moby Thesaurus II by Grady Ward, 1.0:

339 Moby Thesaurus words for "air":
   CAT, Caelus, action, actions, activity, acts, address, advertise,
   aerate, aerodynamics, aerospace, aerosphere, affectation, air,
   air hole, air out, air pocket, air-condition, air-cool, airify,
   airspace, airy nothing, analyze, aria, atmosphere, atom,
   atomic particles, aura, azure, bearing, behavior, behavior pattern,
   behavioral norm, behavioral science, blazon forth, blue sky,
   brandish, break it to, break the news, breathe, breeze, broach,
   broadcast, brow, brute matter, bubble, building block, bump,
   caelum, canopy, canopy of heaven, canto, cantus, canvass, carriage,
   cast, cast of countenance, ceiling, cerulean, chaff,
   chemical element, chip, climate, cobweb, color, come out with,
   comment upon, complexion, component, comportment, conduct, confide,
   confide to, consider, constituent, controvert, cooling breeze,
   cope, cork, countenance, cross-ventilate, crosswind,
   culture pattern, custom, dangle, deal with, debate, declare,
   deliberate, deliberate upon, demeanor, demonstrate, deportment,
   descant, discourse about, discover, discuss, display, divulgate,
   divulge, doing, doings, down, dust, earth, element,
   elementary particle, elementary unit, emblazon, empty space,
   empyrean, ether, evulgate, examine, exchange views, exhibit, face,
   facial appearance, fairy, fan, favor, favorable wind, feather,
   feature, features, feel, feeling, fire, firmament, flash, flaunt,
   flourish, flue, fluff, fluid, foam, fog, folkway, freshen, front,
   froth, fundamental particle, fuzz, gale, garb, gas, gentle wind,
   gestures, give, give out, give vent to, go into, goings-on,
   gossamer, guise, halogen gas, handle, head wind, heaven, heavens,
   high-pressure area, hold up, hole, hyaline, hyle, hypostasis,
   illusion, inert gas, investigate, ionosphere, jetstream,
   knock around, lay, let get around, let in on, let out, lift, lifts,
   light air, light breeze, light wind, line, lineaments, lines,
   looks, low-pressure area, maintien, make known, make public,
   manifest, manner, manners, material, material world, materiality,
   matter, measure, melodia, melodic line, melody, method,
   methodology, methods, mien, milieu, mist, moderate breeze,
   modus vivendi, molecule, monad, mote, motions, movements, moves,
   natural world, nature, noise abroad, note, observable behavior,
   ocean breeze, onshore breeze, open up, out with, overcast,
   overtone, oxygenate, oxygenize, parade, pass under review, pattern,
   phantom, physical world, physiognomy, plenum, pneumatics, pocket,
   poise, port, pose, posture, practice, praxis, presence, procedure,
   proceeding, proclaim, publish, put, put forth, put forward,
   put out, quality, rap, reason, reason about, reason the point,
   refrain, refresh, reveal, review, roughness, sea breeze, sense,
   set, shadow, sift, sky, smoke, social science, softblowing wind,
   solo, solo part, song, soprano part, soup, space, spirit, sponge,
   sport, spume, stance, starry heaven, state, strain, stratosphere,
   straw, study, stuff, style, substance, substratosphere, substratum,
   tactics, tail wind, take up, talk, talk about, talk of, talk over,
   tell, the blue, the blue serene, the four elements, thin air,
   thistledown, thresh out, tone, traits, treat, treble, tropopause,
   troposphere, trough, trumpet, trumpet forth, tune, turbulence,
   turn, undertone, unit of being, utter, vapor, vault,
   vault of heaven, vaunt, vent, ventilate, visage, visibility,
   visibility zero, water, wave, way, way of life, ways, welkin, wind,
   winnow, zephyr



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

AIR
       Adobe Intergrated Runtime (Adobe)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

AIR
       Automatic Image Refinement (Canon), "A.I.R."


The Free On-line Dictionary of Computing (30 December 2018):

AIR

    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

   (1999-10-14)


Easton's 1897 Bible Dictionary:

Air
   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.


The Devil's Dictionary (1881-1906):

AIR, n.  A nutritious substance supplied by a bountiful Providence for
the fattening of the poor.