fluttering

noun3

1. •
   Rapid back-and-forth or up-and-down waving or oscillation of, e.g. wings or a vibrating engine; the condition of engaging in such an action.

   • I was entranced by the colorful fluttering of the butterfly's wings.
   • The valve's fluttering is a problem, you have to find where it comes from.
2. •
   The action of atrial flutter, in which the upper chambers of the heart beat too rapidly.

   • Treatment will reduce the fluttering in your heart.
3. •
   A feeling of internal shifting, as with indigestion, nervous flutters, etc.

   • The fluttering in her belly reminded her that her child was coming one day soon.
   • He felt a fluttering of discontent, but he said nothing.