What is the meaning of fluttering?

noun

• The motion made by flapping up and down.
  • synonyms: flap, flapping, flutter

verb

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