釋義：

Brain：頭腦，腦袋；brainer：費腦筋的事情，與腦袋沒什么關系；

in English：it means anything that requires minimal brain activity to accomplish. Usually said about decisions that are made, implying the decision was easily reached.在英文里，no brainer指的是無需廢腦筋的事情。一般指的是做出了一個決定，而這個決定很簡單就可以做到；

來源：

The decisions we make and the activities we do throughout the day require a brain. 我們所做的決定和行為都需經過大腦的思考。That's right! Even the simplest of tasks require some bit of brain activity to perform. 即使是最簡單的任務都需要一點點大腦的協助.Without a brain, well, we'd be dead and unable to do anything!沒有大腦，生命就會不再，我們也不能做任何事情；

Still, despite this, there are menial tasks or easy decisions that are sometimes considered to be 'no-brainers,' 即使如此，依然有沒有意義的工作和簡單的決定存在，而這些被認為是no brainer; meaning a person shouldn't even have to use their brain to think when performing said tasks or making said decisions. 意思就是說人們在做這些事情和決定的時候根本無需用大腦去思考就可以；For example, if someone is feeling generous and offered you a million dollars for absolutely nothing in return, many would consider the acceptance of that offer to be a 'no-brainer.' 例如： 如果有人很慷慨地免費給你一百萬美元，很多人都會接受，因為這件事就是no brainer;

舉例：

1.一個很漂亮的女孩子主動邀請你去約會：

that was a really easy decision, could be called no brainer. Of course I would go out with her.

2.很多美國公司都是將工廠放在海外代工：

For US firms, the decision to manufacture overseas has long seemed a no-brainer.

對于美國公司來說，去海外生產的決定長時間來似乎是無需考慮的事情。