From 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]