vain

/veɪn/

形容词

虚荣的；自负的
He was very vain about his hair and his clothes.
他很虚荣，在发型和衣着方面非常讲究。
徒劳的；枉然的；无用的
The doctors gave him more powerful drugs in the vain hope that he might recover.
医生们给他服用了更强效的药，希望他能够康复，却是徒然。