Nouns

(n)waver, flutter, flickerthe act of moving back and forth
(n)flutterabnormally rapid beating of the auricles of the heart (especially in a regular rhythm); can result in heart block
(n)disturbance, disruption, commotion, flutter, hurly burly, to-do, hoo-ha, hoo-hah, kerfufflea disorderly outburst or tumult“they were amazed by the furious disturbance they had caused”
(n)flap, flapping, flutter, flutteringthe motion made by flapping up and down

Verbs

(v)flit, flutter, fleet, dartmove along rapidly and lightly; skim or dart“The hummingbird flitted among the branches”
(v)flicker, waver, flitter, flutter, quivermove back and forth very rapidly“the candle flickered”
(v)flutterflap the wings rapidly or fly with flapping movements“The seagulls fluttered overhead”
(v)palpitate, flutterbeat rapidly“His heart palpitated”
(v)bat, flutterwink briefly“bat one's eyelids”