The Collaborative International Dictionary of English v.0.48:

Fly \Fly\ (fl[imac]), v. i. [imp. Flew (fl[=u]); p. p. Flown
   (fl[=o]n); p. pr. & vb. n. Flying.] [OE. fleen, fleen,
   fleyen, flegen, AS. fle['o]gan; akin to D. vliegen, OHG.
   fliogan, G. fliegen, Icel. flj[=u]ga, Sw. flyga, Dan. flyve,
   Goth. us-flaugjan to cause to fly away, blow about, and perh.
   to L. pluma feather, E. plume. [root]84. Cf. Fledge,
   Flight, Flock of animals.]
   1. To move in or pass through the air with wings, as a bird.

   2. To move through the air or before the wind; esp., to pass
      or be driven rapidly through the air by any impulse.
      [1913 Webster]

   3. To float, wave, or rise in the air, as sparks or a flag.
      [1913 Webster]

            Man is born unto trouble, as the sparks fly upward.
                                                  --Job v. 7.
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   4. To move or pass swiftly; to hasten away; to circulate
      rapidly; as, a ship flies on the deep; a top flies around;
      rumor flies.
      [1913 Webster]

            Fly, envious Time, till thou run out thy race.
                                                  --Milton.
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            The dark waves murmured as the ships flew on.
                                                  --Bryant.
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   5. To run from danger; to attempt to escape; to flee; as, an
      enemy or a coward flies. See Note under Flee.
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            Fly, ere evil intercept thy flight.   --Milton.
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            Whither shall I fly to escape their hands ? --Shak.
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   6. To move suddenly, or with violence; to do an act suddenly
      or swiftly; -- usually with a qualifying word; as, a door
      flies open; a bomb flies apart.
      [1913 Webster]

   To fly about (Naut.), to change frequently in a short time;
      -- said of the wind.

   To fly around, to move about in haste. [Colloq.]

   To fly at, to spring toward; to rush on; to attack
      suddenly.

   To fly in the face of, to insult; to assail; to set at
      defiance; to oppose with violence; to act in direct
      opposition to; to resist.

   To fly off, to separate, or become detached suddenly; to
      revolt.

   To fly on, to attack.

   To fly open, to open suddenly, or with violence.

   To fly out.
      (a) To rush out.
      (b) To burst into a passion; to break out into license.

   To let fly.
      (a) To throw or drive with violence; to discharge. "A man
          lets fly his arrow without taking any aim." --Addison.
      (b) (Naut.) To let go suddenly and entirely; as, to let
          fly the sheets.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Flying \Fly"ing\, a. [From Fly, v. i.]
   Moving in the air with, or as with, wings; moving lightly or
   rapidly; intended for rapid movement.
   [1913 Webster]

   Flying army (Mil.) a body of cavalry and infantry, kept in
      motion, to cover its own garrisons and to keep the enemy
      in continual alarm. --Farrow.

   Flying artillery (Mil.), artillery trained to rapid
      evolutions, -- the men being either mounted or trained to
      spring upon the guns and caissons when they change
      position.

   Flying bridge, Flying camp. See under Bridge, and
      Camp.

   Flying buttress (Arch.), a contrivance for taking up the
      thrust of a roof or vault which can not be supported by
      ordinary buttresses. It consists of a straight bar of
      masonry, usually sloping, carried on an arch, and a solid
      pier or buttress sufficient to receive the thrust. The
      word is generally applied only to the straight bar with
      supporting arch.

   Flying colors, flags unfurled and waving in the air; hence:

   To come off with flying colors, to be victorious; to
      succeed thoroughly in an undertaking.

   Flying doe (Zool.), a young female kangaroo.

   Flying dragon.
   (a) (Zool.) See Dragon, 6.
   (b) A meteor. See under Dragon.

   Flying Dutchman.
   (a) A fabled Dutch mariner condemned for his crimes to sail
       the seas till the day of judgment.
   (b) A spectral ship.

   Flying fish. (Zool.) See Flying fish, in the Vocabulary.


   Flying fox (Zool.), see Flying fox in the vocabulary.

   Flying frog (Zool.), either of two East Indian tree frogs
      of the genus Rhacophorus (Rhacophorus nigrapalmatus
      and Rhacophorus pardalis), having very large and broadly
      webbed feet, which serve as parachutes, and enable it to
      make very long leaps.

   Flying gurnard (Zool.), a species of gurnard of the genus
      Cephalacanthus or Dactylopterus, with very large
      pectoral fins, said to be able to fly like the flying
      fish, but not for so great a distance.

   Note: Three species are known; that of the Atlantic is
         Cephalacanthus volitans.

   Flying jib (Naut.), a sail extended outside of the standing
      jib, on the flying-jib boom.

   Flying-jib boom (Naut.), an extension of the jib boom.

   Flying kites (Naut.), light sails carried only in fine
      weather.

   Flying lemur. (Zool.) See Colugo.

   Flying level (Civil Engin.), a reconnoissance level over
      the course of a projected road, canal, etc.

   Flying lizard. (Zool.) See Dragon, n. 6.

   Flying machine, any apparatus for navigating through the
      air, especially a heavier-than-air machine. -- Flying
   mouse (Zool.), the opossum mouse (Acrobates pygm[ae]us), a
      marsupial of Australia. Called also feathertail glider.

   Note: It has lateral folds of skin, like the flying
         squirrels, and a featherlike tail. -- Flying party
      (Mil.), a body of soldiers detailed to hover about an
      enemy. -- Flying phalanger (Zool.), one of several
      species of small marsuupials of the genera Petaurus and
      Belideus, of Australia and New Guinea, having lateral
      folds like those of the flying squirrels. The sugar
      squirrel (Belideus sciureus), and the ariel (Belideus
      ariel), are the best known; -- called also squirrel
      petaurus and flying squirrel. See Sugar squirrel. --
   Flying pinion, the fly of a clock. -- Flying sap (Mil.),
      the rapid construction of trenches (when the enemy's fire
      of case shot precludes the method of simple trenching), by
      means of gabions placed in juxtaposition and filled with
      earth. -- Flying shot, a shot fired at a moving object,
      as a bird on the wing. -- Flying spider. (Zool.) See
      Ballooning spider. -- Flying squid (Zool.), an oceanic
      squid (Ommastrephes Bartramii syn. Sthenoteuthis
      Bartramii), abundant in the Gulf Stream, which is able to
      leap out of the water with such force that it often falls
      on the deck of a vessel. -- Flying squirrel (Zool.) See
      Flying squirrel, in the Vocabulary. -- Flying start, a
      start in a sailing race in which the signal is given while
      the vessels are under way. -- Flying torch (Mil.), a
      torch attached to a long staff and used for signaling at
      night.
      [1913 Webster]

WordNet (r) 3.0 (2006):

flying
    adj 1: moving swiftly; "fast-flying planes"; "played the
           difficult passage with flying fingers" [syn: fast-
           flying, flying]
    2: hurried and brief; "paid a flying visit"; "took a flying
       glance at the book"; "a quick inspection"; "a fast visit"
       [syn: flying, quick, fast]
    n 1: an instance of traveling by air; "flying was still an
         exciting adventure for him" [syn: flight, flying]

Moby Thesaurus II by Grady Ward, 1.0:

148 Moby Thesaurus words for "flying":
   aeronautics, agile, air service, airborne, airline, ascending,
   astronautics, aviation, axial, back, back-flowing, backward,
   ballooning, blind flying, breakneck, brittle, capricious,
   changeable, cloud-seeding, commercial aviation, contact flying,
   corruptible, cruising, cursory, dashing, deciduous, descending,
   disappearing, dissolving, double-quick, down-trending, downward,
   drifting, dying, eagle-winged, ephemeral, evanescent, evaporating,
   expeditious, express, fading, fast, festinate, feverish, fickle,
   fleet, fleeting, flight, flitting, flowing, fluent, fluttering,
   fly-by-night, fragile, frail, fugacious, fugitive, furious,
   galloping, general aviation, gliding, going, gyrational, gyratory,
   hair-trigger, hasty, headlong, hovering, hurried, hustling,
   immediate, impermanent, impetuous, impulsive, inconstant, instant,
   insubstantial, jet-propelled, last-minute, light of heel,
   light-footed, lively, melting, mercurial, momentary, mortal,
   mounting, mutable, nimble, nimble-footed, nondurable, nonpermanent,
   on the spot, passing, perishable, pilotage, plunging, precipitate,
   progressive, prompt, quick, quick as lightning, quick as thought,
   rapid, reckless, reflowing, refluent, regressive, retrogressive,
   rising, rocket-propelled, rotary, rotational, rotatory, running,
   rushing, sailing, sailplaning, short-lived, sideward, sinking,
   slap-bang, slapdash, snap, snappy, soaring, spanking, speedy,
   streaming, superficial, swift, temporal, temporary, transient,
   transitive, transitory, undurable, unenduring, unstable,
   up-trending, upward, urgent, vanishing, volant, volatile, volitant,
   winged, winging