The Collaborative International Dictionary of English v.0.48:

Flit \Flit\, v. i. [imp. & p. p. Flitted; p. pr. & vb. n.
   Flitting.] [OE. flitten, flutten, to carry away; cf. Icel.
   flytja, Sw. flytta, Dan. flytte. [root]84. Cf. Fleet, v.
   i.]
   1. To move with celerity through the air; to fly away with a
      rapid motion; to dart along; to fleet; as, a bird flits
      away; a cloud flits along.
      [1913 Webster]

            A shadow flits before me.             --Tennyson.
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   2. To flutter; to rove on the wing. --Dryden.
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   3. To pass rapidly, as a light substance, from one place to
      another; to remove; to migrate.
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            It became a received opinion, that the souls of men,
            departing this life, did flit out of one body into
            some other.                           --Hooker.
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   4. To remove from one place or habitation to another. [Scot.
      & Prov. Eng.] --Wright. Jamieson.
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   5. To be unstable; to be easily or often moved.
      [1913 Webster]

            And the free soul to flitting air resigned.
                                                  --Dryden.
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The Collaborative International Dictionary of English v.0.48:

Flit \Flit\, a.
   Nimble; quick; swift. [Obs.] See Fleet.
   [1913 Webster]

WordNet (r) 3.0 (2006):

flit
    n 1: a sudden quick movement [syn: flit, dart]
    2: a secret move (to avoid paying debts); "they did a moonlight
       flit"
    v 1: move along rapidly and lightly; skim or dart; "The
         hummingbird flitted among the branches" [syn: flit,
         flutter, fleet, dart]

Moby Thesaurus II by Grady Ward, 1.0:

257 Moby Thesaurus words for "flit":
   advance, aeroplane, air speed, airlift, airplane, auntie,
   ball the jack, balloon, barrel, bat around, be airborne, beat,
   beating, bi-guy, bicker, bisexual, boom, bowl along, breeze,
   breeze along, brush, bull dyke, bum, butch, catamite, celerity,
   chicken, clip, coast, commute, continue, count ties, course,
   cover ground, cruise, cut along, dance, dart, disappear, dispatch,
   divagate, drift, dyke, elapse, emigrate, endure, evanesce,
   evaporate, expatriate, expedition, expire, fade, fag, faggot,
   fairy, fare, fare forth, fastness, femme, ferry, fetch, flap,
   flash, flee, fleet, flick, flicker, flight, flip, flitter, float,
   flop, flow, flow on, flurry, flutter, fly, fly low, foot,
   fricatrice, fruit, gad, gad about, gallivant, gang, glide,
   glissade, go, go about, go along, go by, go fast, go on,
   go pitapat, go the rounds, ground speed, gunsel, gutter, haste,
   hasten, hie, highball, hit the road, hit the trail, hobo, homo,
   homophile, homosexual, homosexualist, hop, hover, hurry,
   hydroplane, ice-skate, immigrate, in-migrate, instantaneousness,
   intermigrate, invert, jaunt, jet, knock about, knock around, knots,
   lapse, last, lesbian, lightning speed, make knots, meander, melt,
   melt like snow, migrate, miles per hour, mooch, move, move along,
   move on, nance, navigate, nip, nomadize, out-migrate,
   outstrip the wind, palpitate, palpitation, pansy, pass, pass away,
   pass by, pathic, peregrinate, pererrate, pitapat, pitter-patter,
   pour it on, precipitation, press on, proceed, progress,
   promptitude, promptness, prowl, pulse, punk, queen, queer,
   quickness, quiver, ramble, range, rapidity, remigrate, rip, roam,
   roll, roll on, roller-skate, round pace, rove, rpm, run, run about,
   run its course, run on, run out, rush, sail, sailplane, sapphist,
   sashay, saunter, scorch, scud, seaplane, shake, sideslip, sink,
   sizzle, skate, skateboard, ski, skid, skim, skip, slat, sled,
   sleigh, slide, slip, slither, snappiness, soar, speed, speediness,
   splutter, sputter, storm along, straggle, stray, stream, stroll,
   swarm, sweep, swift rate, swiftness, take the air, take wing,
   tatter, tear, tear along, throb, thunder along, toboggan, traipse,
   tramp, transmigrate, travel, trek, tribade, vagabond, vagabondize,
   vanish, velocity, volplane, walk the tracks, wander, wave, waver,
   wayfare, wend, whisk, whiz, wing, zing, zip, zoom