“fluttering” 通常指(轻快、断续地)拍动、飘动、振翅;也可引申为(心脏)怦怦乱跳或(情绪)忐忑不安的感觉。(源自动词 flutter 的现在分词/动名词形式。)
/ˈflʌtərɪŋ/
The bird was fluttering its wings in the cage.
那只鸟在笼子里扑腾着翅膀。
Fluttering in the wind, the torn flag made a soft, restless sound that matched his uneasy thoughts.
破旗在风中飘动,发出轻微而不安的声响,正映照了他忐忑的思绪。
flutter 可能来自中古英语,属于拟声/描摹动作的词,模仿轻快拍动时“扑簌扑簌”的感觉;后逐渐固定为表示“轻微快速地拍动、飘动”,并引申到“心跳加速、紧张不安”等抽象含义。