If you are careless, you do not pay enough attention to what you are doing, and so you make mistakes, or cause harm or damage.
双语例句
例： I'm sorry. How careless of me.
对不起，我太粗心了。
例： Some parents are accused of being careless with their children's health.
有些父母被指责对孩子的健康掉以轻心。