that does not produce the result you want 徒劳的；枉然的；无结果的 She closed her eyes tightly in a vain attempt to hold back the tears. 她紧闭双眼，却无法忍住眼泪。 I knocked loudly in the vain hope that someone might answer. 我敲门敲得很响，希望有人应声，却是徒然。 The government spent billions in a vain bid to prop up the currency. 政府花费数十亿美元试图支撑货币，但徒劳无功。
Homophones vain | veinvain veinTopics Difficulty and failurec2- vain adjective
He plunged into the icy water in a vain effort to rescue his dog. 他跳入冰冷的水中，徒劳地试图去救他的狗。
- vein noun
A vein in her head throbbed when she was angry. 她生气时，头上的一根血管在颤动。
- (disapproving)
too proud of your own appearance, abilities or achievements 自负的；自视过高的 Extra ExamplesTopics Personal qualitiesc1Their flattery made him vain. 他们的吹捧使他自命不凡。 very vain about his looks 对自己的外表非常自负 He's so vain! 他太自负了！ I don't think it's vain to care about how you look. 我并不认为注重自己的容貌就是爱慕虚荣。
Word OriginMiddle English (in the sense ‘without real worth’): via Old French from Latin vanus ‘empty, without substance’.
Idioms
in vain
without success 枉费心机；徒劳无益；白费力气 They tried in vain to persuade her to go. 他们极力劝说她去，但枉费了一番口舌。 She waited in vain for her son to return. 她等着儿子归来，但空等了一场。 All our efforts were in vain. 我们的所有努力都付诸东流了。
take somebody’s name in vain