"flap" in Chinese (Simplified)
翻盖拍动拍打
Definition
翻盖指可以上下活动的薄片部分，如信封的盖子或鸟的翅膀。也可以指快速上下拍动，尤其是指翅膀或手臂。
Usage Notes (Chinese (Simplified))
“Flap”既可以做名词（信封翻盖、飞机翼等），又可以做动词（拍动、拍打）。在航空和医学等技术领域很常见。不要与“slap”（拍打/掌掴）混淆。口语中有时表示小混乱。
Examples
The flap of the envelope was open.
信封的**翻盖**是开的。
Birds flap their wings to fly.
鸟儿**拍打**翅膀来飞。
Please close the flap on your backpack.
请把你的背包**翻盖**合上。
Don't get in a flap about being late, it's fine.
别为迟到感到**慌乱**，没关系。
She started to flap her hands excitedly.
她激动地开始**挥动**双手。
The pilot lowered the flaps before landing.
飞行员在降落前放下了**襟翼**。