pron.

1. （反身代词）自己，自身
   One shouldn't overwork oneself.

   一个人不应该过分劳累。

2. 亲自，本人
   To do something oneself is often easier than getting someone else to do it.

   自己去办理一件事常常比请人去做来得容易。

pron.

1. [reflexive] used as the object of a verb or preposition when this is the same as the subject of the clause and the subject is ‘one’.
2. [emphatic] used to emphasize that one does something individually or unaided.
3. in one's normal and individual state of body or mind.