The Collaborative International Dictionary of English v.0.48:

Flutter \Flut"ter\, v. t.
   1. To vibrate or move quickly; as, a bird flutters its wings.
      [1913 Webster]

   2. To drive in disorder; to throw into confusion.
      [1913 Webster]

            Like an eagle in a dovecote, I
            Fluttered your Volscians in Corioli.  --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Flutter \Flut"ter\, n.
   1. The act of fluttering; quick and irregular motion;
      vibration; as, the flutter of a fan.
      [1913 Webster]

            The chirp and flutter of some single bird --Milnes.
                                                  .
      [1913 Webster]

   2. Hurry; tumult; agitation of the mind; confusion; disorder.
      --Pope.
      [1913 Webster]

   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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

flutter
    n 1: the act of moving back and forth [syn: waver, flutter,
         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, flutter, hurly burly, to-do,
       hoo-ha, hoo-hah, kerfuffle]
    4: the motion made by flapping up and down [syn: flap,
       flapping, flutter, fluttering]
    v 1: move along rapidly and lightly; skim or dart; "The
         hummingbird flitted among the branches" [syn: flit,
         flutter, fleet, dart]
    2: move back and forth very rapidly; "the candle flickered"
       [syn: flicker, waver, flitter, flutter, quiver]
    3: flap the wings rapidly or fly with flapping movements; "The
       seagulls fluttered overhead"
    4: beat rapidly; "His heart palpitated" [syn: palpitate,
       flutter]
    5: wink briefly; "bat one's eyelids" [syn: bat, flutter]