n. 1
The act of fluttering, or multiple acts thereof; the back-and-forth motion of fluttering; a state of fluttering. The rapid up-and-down movement of the eyelids, and consequently eyelashes, often seen as intentionally flirtatious or alluring and often attributed to the eyes or eyebrows.
He couldn't help but feel more attracted to her with each flutter of her eyes/lashes/eyelids.
n. 2
A spasmodic vibration of one or more body parts or the entire body; a shudder. A flash of emotion that accompanies an internal sensation, such as a rapid pulsation of the heart or a quiver of nervous disquiet; a small burst of emotion that may be felt or expressed; a fleeting feeling or idea experienced as a feeling.
flutter of pain, agony, etc.; flutter of interest, learning, knowledge
v. 1
To flap or wave quickly but irregularly.
flags fluttering in the wind
v. 2
Of a winged animal: to flap the wings without flying; to fly with a light flapping of the wings.

Related words

Word family: flutterball flutterboard
Phrases: atrial flutter auricular flutter

Forms

Plural: flutters → flickers, quivers, tremors, palpitations…
Past participle: fluttered
e.g. fluttered → flitted, darted, fleeted, flyed…

Choose the right word

Flutter, Flap, Fluctuate, Flaps or Flutters?

Flap, flutter, and fluctuate refer to wave-like movements, flap generally to such as produce a sharp sound; a cock flaps his wings; flutter applies to a less pronounced and more irregular motion; a captive bird or a feeble pulse flutters.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

flicker I noticed a flicker of hesitation in their eyes.
tremor The poor woman was struck with a nervous tremor.
quiver From tears to a kiss, there is naught but a quiver!
commotion James heard the commotion and hurried to the room.
flurry Everyone hoped for a snow flurry for Christmas.

Popularity over time

Word	1850 → 2019	Trend
flutter		steady
flicker		rising
tremor		rising
quiver		rising
palpitation		falling
commotion		rising

Use in printed books, per decade from 1850 to 2019.

By length

3 letters: fly¹, bat¹, ado²
4 letters: kick¹, wave¹, dose¹, stir¹, fuss¹, flap¹, dart¹, flit¹
5 letters: shake¹, fleet¹, hurry², flare¹, quake¹, swarm¹, hover², spasm², waver²
6 letters: bother², thrill¹, rumble², rattle², flurry², tremor², shiver², wobble², flaunt¹, quiver², ruffle², twinge¹, pucker², quaver²
7 letters: trouble², batting², confuse², chatter², twinkle², flicker², shudder², vibrate², tremble², hiccups², agitate³, frisson, perturb², fluster²
8 letters: disorder³, flapping², unsettle³
9 letters: confusion³, vibration³, trembling³, agitation⁴, commotion³, fluctuate³, oscillate³, kerfuffle³, vacillate³, palpitate³
10 letters: disruption³, hullabaloo⁴
11 letters: disturbance³, trepidation⁴, palpitation⁴
12 letters: perturbation⁴

The small number after each word is its number of syllables (ado² = 2 syllables).

In other languages

Français: flottement
Italiano: galleggiamento