Source : Webster's Revised Unabridged Dictionary (1913)

Flutter \Flut"ter\, v. t.
   1. To vibrate or move quickly; as, a bird flutters its wings.

   2. To drive in disorder; to throw into confusion.

            Like an eagle in a dovecote, I Fluttered your
            Volscians in Corioli.                 --Shak.

Flutter \Flut"ter\, n.
   1. The act of fluttering; quick and irregular motion;
      vibration; as, the flutter of a fan.

            The chirp and flutter of some single bird --Milnes.
                                                  .

   2. Hurry; tumult; agitation of the mind; confusion; disorder.
      --Pope.

   {Flutter wheel}, a water wheel placed below a fall or in a
      chute where rapidly moving water strikes the tips of the
      floats; -- so called from the spattering, and the
      fluttering noise it makes.

Source : WordNet®

flutter
     n 1: the act of moving back and forth [syn: {waver}, {flicker}]
     2: abnormally rapid beating of the auricles of the heart
        (especially in a regular rhythm); can result in heart
        block
     3: a disorderly outburst or tumult; "they were amazed by the
        furious disturbance they had caused" [syn: {disturbance},
        {disruption}, {commotion}, {stir}, {hurly burly}, {to-do},
         {hoo-ha}, {hoo-hah}, {kerfuffle}]
     4: the motion made by flapping up and down [syn: {flap}, {flapping},
         {fluttering}]
     v 1: move along rapidly and lightly; skim or dart [syn: {flit}, {fleet},
           {dart}]
     2: move back and forth very rapidly; "the candle flickered"
        [syn: {flicker}, {waver}, {flitter}, {quiver}]
     3: beat rapidly; "His heart palpitated" [syn: {palpitate}]
     4: wink briefly; "bat one's eyelids" [syn: {bat}]