will have been fluttering

• future perfect progressive

  future perfect progressive

  Used to describe a continuous action that will progress up until a designated point of completion in the future.

  of flutter.
  flutter

  verb (used without object)

  to wave, flap, or toss about.

Related Words

• drift
• flicker
• flit
• flop
• hover
• quiver
• shiver
• throb
• tremble
• vibrate
• wiggle
• wobble