Room, margin, or scope for something—space left for change, improvement, or discussion (e.g., 'room for improvement').
まだ改善の余地がある。
There is still room for improvement.
その意見には議論の余地がある。
There is room for debate on that opinion.
余地がないため、計画を変更した。
Because there was no leeway, the plan was changed.