Definition
To focus all one's energy and effort on a specific task.
努力工作，全力以赴
I need to get my head down and finish this proposal to meet the deadline.
我需要專心完成這份提案以趕上截止日期。
The exams are coming up, you should really get your head down and study.
考試快到了，你真的應該專心讀書。
In the final stage of the project, we all need to get our heads down and get everything finished.
在專案的最後階段，我們都需要專心完成所有事情。