1to assign
2to appoint
3to take up a post
4office
5responsibility
6to let
7to allow
8to give free rein to
9no matter (how, what etc)
10classifier for terms served in office, or for spouses, girlfriends etc (as in 前任男友)
Examples
wǒ我xiàn zài现在zài在zhè这suǒ所xué xiào学校rèn任jiāo教。
我现在在这所学校任教。
I'm currently a teacher at this school.
我第一任妻子去世了。
My first wife is dead.
这是我第一任丈夫的第二任妻子。
This is my first husband's second wife.