1、adv. 副詞：
在夜間；在晚上 during or for the night
例：We stayed overnight in London after the theatre. 我們看完戲後在倫敦住了壹晚。
突然；壹夜之間；旋即 suddenly or quickly
例：Don't expect it to improve overnight. 不要指望這事壹下子就改善了。
2、adj. 形容詞：
夜間的；晚上的；只供壹夜的 happening during the night; for a night
例：an overnight flight 夜間飛行
突然的；很快的；壹夜之間的 happening suddenly or quickly
例：The play was an overnight success. 這部劇作壹夜成名。
3、verb. 動詞：
例：They had told her she would be overnighting in Sydney. 他們跟她說過她將在悉尼過夜。
擴展資料
overnight 有關諺語：
1、Rice is afraid of cold dew and frost overnight, wheat is afraid of clear and bright rain.? 稻怕寒露壹夜霜，麥怕清明連放雨。
2、Success doesn't happen overnight.? 成功不會壹夜間發生。
參考資料
百度翻譯——overnight