Used for being partway through a journey, task, or process. Often implies that the goal is not yet reached.
道半ばで引き返すわけにはいかない。
We can't turn back when we're only halfway.
プロジェクトはまだ道半ばだ。
The project is still only halfway done.
Compound of 道 (path, way) and 半ば (half, middle). The literal meaning 'halfway along the path' extends metaphorically to any endeavor.