剑背后沿的英文：
back edge（脉冲）

back是什么意思：
n. 后面，背面，反面；背，背部；靠背；后卫
v. 支持；后退，倒退；背书；下赌注于
adj. 背部的；后面的；过去的；拖欠的.
adv. 以前；向后地；来回地；上溯

Stand back to back!
背靠背站好！

They are on the back of the menu.
它们在菜单背面。

Our seats on the train were back to back.
我们在火车上的坐位是背靠背的。

It happened far back in the past.
这事发生在久远的过去。

the back of a Chinese robe or jacket
后襟

edge是什么意思：
n. 边，边缘；刀，刀口
v. 使徐徐移动；给...加边

The number of incoming edges is equal to the number of outgoing edges
进入的线数等于离去的线数。

pipe edges sewing machine
滚边缝纫机

Sloth turneth the edge of wit
懒惰会磨去才智的锋芒

The knife's edges have blunted.
这刀刃已变钝了。

Gripper edge: Edge of a sheet to be gripped by the grippers of a printing machine.Also called Feed edge,Leading edge.
夹牙边:被印刷机上的夹牙抓牢的纸边。亦称前纸边，纸头。