thoughtlessness
/ˈθɔːtləsnəs/ 16a lack of thought about how your actions or words may upset someone: Many of the world's injustices are caused by human greed or thoughtlessness.
noun [专属名词]欠考虑；不体贴
He repented his thoughtlessness.他后悔自己的轻率。
单词造句:
He repented his thoughtlessness.他后悔自己的轻率。