Answer: fluttering

AnswerCrossword Clue
FLUTTERINGLike a nervous stomach
fluttering(with reference to a bird's wings) Flap in such a way
fluttering(of a pulse or heartbeat) Beat feebly or irregularly
flutteringFLUTTER, to move in quick motions
fluttering(of a bird or other winged creature) Fly unsteadily or hover by flapping the wings quickly and lightly
fluttering(of a person) Move restlessly or uncertainly
flutteringMove or fall with a light irregular or trembling motion