vainKK [ven] /veɪn/發音形容詞1自負的、虛榮的、愛慕虛榮的貶義He is so vain that he checks his reflection in every window.他非常自負,經過每片玻璃都要照一下自己。2徒勞的、無效的、白費的They made a vain attempt to save the flooded basement.他們試圖搶救淹水的地下室,但徒勞無功。3空虛的、無價值的正式His promises turned out to be nothing but vain words.他的承諾到頭來只是空話。片語1白費、徒然、枉然We waited three hours in vain for the delayed train.我們白等了三個小時,那班誤點的火車始終沒來。