margin
/ˈmɑrʤən/
the boundary line or the area immediately inside the boundary
Chinese meaning: 边缘；余地
The river flows along the eastern margin of the forest.
河流沿着森林的东边缘流淌。
She wrote notes in the margin of the textbook for revision.
她在教科书的页边空白处写下笔记以便复习。