the part of a book that faces inward when the book is shelved; the part opposite the spine
例句
用作名词 (n.)
I walked along the outer edge of the track. 我沿着跑道的外缘走。
After adding that circle, now we can draw two straight lines from the edge of the circle.This will make Mara's strong arms. 加上那个圈以后,我们现在就可以沿圈的外缘画两条直线,这是玛拉强壮的手臂。