详细解释:a. 粗心的, 不关心的, 无忧无虑的
词型变化：
名词:carelessness副词:carelessly英语解释：
形容词 careless:
marked by lack of attention or consideration or forethought or thoroughness; not carefuleffortless and unstudied(usually followed by `of') without due thought or consideration同义词：regardless