What is the meaning of flutter?

noun

• The act of moving back and forth.
  • synonyms: waver, flicker
• Abnormally rapid beating of the auricles of the heart (especially in a regular rhythm); can result in heart block.
• A disorderly outburst or tumult.
  • usage: "they were amazed by the furious disturbance they had caused"
  • synonyms: disturbance, disruption, commotion, hurly burly, to-do, hoo-ha, hoo-hah, kerfuffle
• The motion made by flapping up and down.
  • synonyms: flap, flapping, fluttering

verb

• Move along rapidly and lightly; skim or dart.
  • usage: "The hummingbird flitted among the branches"
  • synonyms: flit, fleet, dart
• Move back and forth very rapidly.
  • usage: "the candle flickered"
  • synonyms: flicker, waver, flitter, quiver
• Flap the wings rapidly or fly with flapping movements.
  • usage: "The seagulls fluttered overhead"
• Beat rapidly.
  • usage: "His heart palpitated"
  • synonyms: palpitate
• Wink briefly.
  • usage: "bat one's eyelids"
  • synonyms: bat