中英成语俚语800对120：掉以轻心
掉以轻心 Make it lightly. Make light of. Lower one's guard.
eg：It's an important job，you must not take it lightly.
中英俚语俗语来源：柳宗元·论师道书：“故吾每为文章，未尝敢以轻心掉之。”
同义词：毫不在意 To make nothing of. 反义词：严阵以待 Poised for action.