1. They tried in vain to open the locked door.
    他们妄图打开锁着的门。

2. We tried vainly to discover what had happened.
    我们设法想要弄清楚发生了什么事，但却徒劳。

1. danci.911cha.com

1. 徒劳地：vainglory 自负 | vainly 徒劳地 | vainness 无益

2. 枉然的/无益地/徒然/自夸地/自负的：vainglory /虚荣/ | vainly /枉然的/无益地/徒然/自夸地/自负的/ | vainness /无益/徒然/自负/

1. to no avail

    e.g. he looked for her in vain
           the city fathers tried vainly to find a solution

    Synonym: in vain