If you say that someone is reckless, you mean that they act in a way which shows that they do not care about danger or the effect their behaviour will have on other people.
例句
She loved to ride; on horseback, she was reckless and utterly without fear...她喜欢骑马；在马背上，她纵横驰骋，毫无畏惧。He is charged with causing death by reckless driving.他被控危险驾驶致人死亡。
英汉词典释义
adv.
不在乎地;鲁莽地;不顾一切地
He was arrested for driving recklessly.他因鲁莽开车被捕。If you drive as recklessly as that,you’ll end in hospital.要是你开车老是那样鲁莽,总有一天要住进医院。He drove so recklessly that he collided with a tree and landed up in hospital.他开车太鲁莽,结果撞到一棵树上,最终进了医院。