flutter

flutter verb uk/ˈflʌtər/ us
[ I,T ] to move quickly and gently up and down or from side to side in the air, or to make something move in this way

колыхаться, развеваться
The flag was flutter ing in the breeze.  flutter about/around/down, etc
to move somewhere quickly and gently, usually without any particular purpose

трепетать, порхать
There were several moths flutter ing around the light.

FLUTTER noun

[ C ] uk/ˈflʌtər/ us flutter noun [C]
(EMOTION)

a state of excitement or worry

трепет, волнение
a flutter of excitement flutter noun [C]