Definition
To do something independently and voluntarily, without being asked or instructed by anyone else.
在沒有任何人的指示或要求下主動去做某事；自行決定做某事
He wasn't asked to do so, he contacted the client off his own bat.
他沒有被要求這麼做，是他自己主動聯繫客戶的。
I didn't expect her to decide to help; she did it off her own bat.
我沒想到她會決定幫忙；她是自願這麼做的。
The manager didn’t ask me to write the report, but I did it off my own bat.
經理沒有要求我寫報告，但我主動寫了。