1 [intransitive and transitive]HBI if a bird or insect flutters,
or if it flutters its wings, it flies by moving its wings
lightly up and down: A small bird fluttered past the window. to
make small gentle movements in the air: Dead leaves fluttered
slowly to the ground. The flag fluttered in the light breeze. if
your heart or your stomach flutters, you feel very excited or
nervous if your eyelids flutter, they move slightly when you are
asleep: Her eyelids fluttered but did not open. if a woman
flutters her eyelashes at a man, she looks at him and moves her
eyes to make herself attractive to him