1to accomplish; to achieve; to carry out something to completion (transitive)
彼は苦労の末、難しいプロジェクトを成し遂げた。
After much hardship, he accomplished the difficult project.
目標を成し遂げるために、計画を立て直した。
We revised the plan to achieve the goal.
約束を成し遂げる責任がある。
You have a responsibility to fulfill your promise.