flap² v -pped, -pping 1 [T] if a bird flaps its wings, it moves them up and down 〔鸟〕振〔翼〕，扑动〔翅膀〕 2 [I] if a piece of cloth, paper etc flaps, it moves around quickly and makes a noise〔布片、纸片等〕呼啦呼啦地飘动: The ship's sails flapped in the wind. 船帆在风中飘动。 3 [I] BrE informal to behave in an anxious and excited way 【英，非正式】 不安，焦急; 激动: There's no need to flap. 不必焦急。