to wave or cause to wave rapidly; flap

(of birds, butterflies, etc) to flap the wings

to move, esp downwards, with an irregular motion

(of the auricles of the heart) to beat abnormally rapidly, esp in a regular rhythm

to be or make nervous or restless

to move about restlessly

to cause (the legs) to move up and down in a flutter kick or (of the legs) to move in this way

to wager or gamble (a small amount of money)

a quick flapping or vibrating motion

a state of nervous excitement or confusion

excited interest; sensation; stir

a modest bet or wager

an abnormally rapid beating of the auricles of the heart (200 to 400 beats per minute), esp in a regular rhythm, sometimes resulting in heart block

a slow variation in pitch in a sound-reproducing system, similar to wow but occurring at higher frequencies

a potentially dangerous oscillation of an aircraft, or part of an aircraft, caused by the interaction of aerodynamic forces, structural elastic reactions, and inertia

a method of sounding a wind instrument, esp the flute, with a rolling movement of the tongue