The Collaborative International Dictionary of English v.0.48:

Windy \Wind"y\, a. [Compar. Windier; superl. Windiest.] [AS.
   windig.]
   [1913 Webster]
   1. Consisting of wind; accompanied or characterized by wind;
      exposed to wind. "The windy hill." --M. Arnold.
      [1913 Webster]

            Blown with the windy tempest of my heart. --Shak.
      [1913 Webster]

   2. Next the wind; windward.
      [1913 Webster]

            It keeps on the windy side of care.   --Shak.
      [1913 Webster]

   3. Tempestuous; boisterous; as, windy weather.
      [1913 Webster]

   4. Serving to occasion wind or gas in the intestines;
      flatulent; as, windy food.
      [1913 Webster]

   5. Attended or caused by wind, or gas, in the intestines. "A
      windy colic." --Arbuthnot.
      [1913 Webster]

   6. Fig.: Empty; airy. "Windy joy." --Milton.
      [1913 Webster]

            Here's that windy applause, that poor, transitory
            pleasure, for which I was dishonored. --South.
      [1913 Webster]

WordNet (r) 3.0 (2006):

windy
    adj 1: abounding in or exposed to the wind or breezes; "blowy
           weather"; "a windy bluff" [syn: blowy, breezy,
           windy]
    2: not practical or realizable; speculative; "airy theories
       about socioeconomic improvement"; "visionary schemes for
       getting rich" [syn: airy, impractical, visionary,
       Laputan, windy]
    3: resembling the wind in speed, force, or variability; "a windy
       dash home"
    4: using or containing too many words; "long-winded (or windy)
       speakers"; "verbose and ineffective instructional methods";
       "newspapers of the day printed long wordy editorials";
       "proceedings were delayed by wordy disputes" [syn: long-
       winded, tedious, verbose, windy, wordy]

Moby Thesaurus II by Grady Ward, 1.0:

162 Moby Thesaurus words for "windy":
   adulterated, aeolian, air-built, airish, airy, all jaw, asinine,
   attenuate, attenuated, big, blasty, bloated, blown up, blowy,
   blustering, blusterous, blustery, bombastic, boreal, breezy, brisk,
   candid, catchpenny, chatty, chimerical, cloud-built, communicative,
   conversational, cut, de longue haleine, diffuse, dilated, dilute,
   diluted, distended, drafty, dreamlike, dropsical, edematous,
   effusive, empty, enchymatous, endless, ethereal, expansive,
   extended, extravagant, fanciful, fat, fatuitous, fatuous, favonian,
   filled out, fine, flatulent, flawy, flimsy, flip, fluent, foolish,
   frank, fresh, fribble, fribbling, frivolous, frothy, fustian,
   futile, gabby, garrulous, gaseous, gassy, glib, gossamery, gossipy,
   gregarious, gushy, gusty, high-flown, high-swelling, highfalutin,
   highfaluting, idle, illusory, imaginary, inane, incrassate,
   inflated, insubstantial, lengthy, light, long, long-drawn-out,
   long-spun, long-winded, longiloquent, loquacious, mouthy,
   multiloquent, multiloquious, newsy, nugacious, nugatory, otiose,
   overblown, overtalkative, padded, phantomlike, plethoric,
   pretentious, prolix, protracted, puffed up, puffy, pursy, rare,
   rarefied, redundant, shadowy, shallow, silly, slender, slight,
   smooth, sociable, spirituous, spun-out, squally, subtile, subtle,
   superficial, swelled, swollen, talkative, talky, tall, tenuous,
   thin, thinned, thinned-out, trifling, trite, trivial, tumescent,
   tumid, turgescent, turgid, uncompact, uncompressed, unreal,
   unrelenting, unsubstantial, vacuous, vain, vapid, vaporous,
   ventose, verbose, voluble, watered, watered-down, wordy