A border or dividing line between places or states; a clear boundary or dividing point.
山と平野の境目に小さな集落がある。
There is a small settlement at the boundary between the mountains and the plain.
成功と失敗の境目はほんの少しの差だ。
The line between success and failure is a very small difference.
古い市街地と新興住宅地の境目を歩いた。
I walked along the border between the old downtown and the new residential area.