The Collaborative International Dictionary of English v.0.48:

Airy \Air"y\, a.
   1. Consisting of air; as, an airy substance; the airy parts
      of bodies.
      [1913 Webster]

   2. Relating or belonging to air; high in air; a["e]rial; as,
      an airy flight. "The airy region." --Milton.
      [1913 Webster]

   3. Open to a free current of air; exposed to the air; breezy;
      as, an airy situation.
      [1913 Webster]

   4. Resembling air; thin; unsubstantial; not material;
      airlike. "An airy spirit." --Shak.
      [1913 Webster]

   5. Relating to the spirit or soul; delicate; graceful; as,
      airy music.
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   6. Without reality; having no solid foundation; empty;
      trifling; visionary. "Airy fame." --Shak.
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            Empty sound, and airy notions.        --Roscommon.
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   7. Light of heart; vivacious; sprightly; flippant;
      superficial. "Merry and airy." --Jer. Taylor.
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   8. Having an affected manner; being in the habit of putting
      on airs; affectedly grand. [Colloq.]
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   9. (Paint.) Having the light and a["e]rial tints true to
      nature. --Elmes.
      [1913 Webster]

WordNet (r) 3.0 (2006):

airy
    adj 1: open to or abounding in fresh air; "airy rooms" [syn:
           aired, airy]
    2: not practical or realizable; speculative; "airy theories
       about socioeconomic improvement"; "visionary schemes for
       getting rich" [syn: airy, impractical, visionary,
       Laputan, windy]
    3: having little or no perceptible weight; so light as to
       resemble air; "airy gauze curtains"
    4: characterized by lightness and insubstantiality; as
       impalpable or intangible as air; "figures light and aeriform
       come unlooked for and melt away"- Thomas Carlyle; "aerial
       fancies"; "an airy apparition"; "physical rather than
       ethereal forms" [syn: aeriform, aerial, airy, aery,
       ethereal]

Moby Thesaurus II by Grady Ward, 1.0:

331 Moby Thesaurus words for "airy":
   Barmecidal, Barmecide, Olympian, adulterated, aeolian, aerial,
   aeriform, aerodynamic, aerostatic, aery, air-built, airish,
   airlike, airy, alfresco, altitudinous, animated, apparent,
   apparitional, ascending, asinine, asomatous, aspiring, astral,
   atmospheric, attenuate, attenuated, autistic, blasty, blowy,
   blustering, blusterous, blustery, bodiless, boreal, bouncy, boyish,
   breezy, brisk, bubbly, buoyant, carefree, careless, casual,
   catchpenny, chimeric, chimerical, cloud-built, colossal, corky,
   cursory, cut, dainty, debonair, decarnate, decarnated, deceptive,
   degage, delicate, delusional, delusionary, delusive, delusory,
   dereistic, diaphanous, dilute, diluted, discarnate, disembodied,
   disregardant, disregardful, dominating, downy, drafty, dreamlike,
   dreamy, easygoing, effervescent, elevated, eminent, empty,
   erroneous, ethereal, exalted, expansive, exposed, exquisite,
   extramundane, fallacious, false, fanciful, fantastic, fatuitous,
   fatuous, favonian, feathery, fine, fine-drawn, finespun, flawy,
   flimsy, flippant, fluffy, foamy, foolish, forgetful, frail,
   free and easy, fresh, fribble, fribbling, frivolous, frothy,
   fuming, fumy, futile, gaseous, gasified, gasiform, gaslike, gassy,
   gauzy, ghostly, girlish, gossamer, gossamery, gracile, gusty,
   haughty, heedless, high, high-pitched, high-reaching, high-set,
   high-spirited, high-up, idealistic, idle, illusional, illusionary,
   illusive, illusory, imaginary, immaterial, impalpable,
   imponderable, imponderous, impractical, in the clouds, inane,
   inconsiderate, incorporate, incorporeal, indifferent, insouciant,
   insubstantial, intangible, jaunty, lacy, lazy, leger, light,
   light as air, lighter than vanity, lighthearted, lightsome, lofty,
   mephitic, miasmal, miasmatic, miasmic, misleading, misty,
   monumental, mounting, mousse, nonmaterial, nonphysical, nugacious,
   nugatory, oblivious, occult, offhand, open-air, ostensible,
   otherworldly, otiose, outtopping, overlooking, overtopping,
   oxyacetylene, oxygenous, ozonic, papery, perfunctory, perky,
   phantasmagoric, phantasmal, phantom, phantomlike, pneumatic,
   poetic, prominent, psychic, puffy, quixotic, rare, rarefied,
   reckless, reeking, reeky, regardless, resilient, respectless,
   romancing, romantic, romanticized, roomy, seeming, self-deceptive,
   self-deluding, shadowy, shallow, silly, skyscraping, slender,
   slenderish, slight, slight-made, slim, slimmish, slinky, small,
   smoking, smoky, soaring, souffle, specious, spectral, spiring,
   spirited, spiritual, spirituous, squally, starry-eyed, steaming,
   steamy, steep, storybook, sublime, subtile, subtle, superficial,
   superlative, supernal, supernatural, supposititious, svelte,
   sylphlike, tactless, tenuous, thin, thin-bodied, thin-set,
   thin-spun, thinned, thinned-out, thinnish, thoughtless, threadlike,
   topless, toplofty, topping, towering, towery, transcendental,
   transmundane, trifling, trite, trivial, tropospheric, unactual,
   uncompact, uncompressed, undiplomatic, unearthly, unembodied,
   unextended, unfleshly, unfounded, unheavy, unheedful, unheeding,
   unmindful, unphysical, unpractical, unprepared, unready, unreal,
   unrealistic, unsolicitous, unsubstantial, untactful, unthinking,
   unworldly, uplifted, upreared, vacuous, vague, vain, vapid,
   vaporing, vaporish, vaporlike, vaporous, vapory, visionary,
   volatile, wasp-waisted, watered, watered-down, watery, weak,
   weightless, willowy, windswept, windy, wiredrawn, wish-fulfilling,
   wispy, yeasty