1.徒然的,无益的,没效果的;愚蠢的;不足道的
2.空的,空虚的;虚有其表的,表面好看的,虚饰的
3.自夸的,自负的;爱虚荣的
1.someone who is vain is very proud and thinks they are very attractive or special
2.unsuccessful, or useless