to do something unexpected that surprises and sometimes worries a person or animal

She was concentrating on her book and his voice startled her. 她正在聚精会神地看书，被他的声音吓了一跳。

The noise of the car startled the birds and the whole flock flew up into the air. 汽车声把一大群鸟惊吓得呼啦啦地飞了起来。

Her article on diet startled many people into changing their eating habits. 她那篇有关饮食的文章使很多人惶惶不安，开始改变饮食习惯。