flap

1. V-T/V-I If something such as a piece of cloth or paper flaps or if you flap it, it moves quickly up and down or from side to side. 使快速擺動; 快速擺動

Grey sheets flapped on the clothes line. 灰色的牀單在晾衣繩上飄動。

2. V-T/V-I If a bird or insect flaps its wings or if its wings flap, the wings move quickly up and down. 快速振動 (翅膀)

The bird flapped its wings furiously. 那衹鳥兒使勁地拍打著翅膀。

3. V-T If you flap your arms, you move them quickly up and down as if they were the wings of a bird. (雙臂像小鳥般) 扇動

...a kid running and flapping her arms. …一個邊跑邊像小鳥一樣上下扇動著雙臂的小女孩。

4. N-COUNT A flap of cloth or skin, for example, is a flat piece of it that can move freely up and down or from side to side because it is held or attached by only one edge. (一耑固定、可自由掀動的佈或皮的) 垂懸平片

He drew back the tent flap and strode out into the blizzard. 他拉開帳篷的門簾，大步走進了暴風雪中。

5. N-COUNT A flap on the wing of an aircraft is an area along the edge of the wing that can be raised or lowered to control the movement of the aircraft. (飛機的) 副翼

...the sudden slowing as the flaps were lowered. …副翼降下時的突然減速。