灰缝的英文：
mortar joint

mortar是什么意思：
n. 灰泥；迫击炮；臼
v. 用迫击炮攻击；用灰泥涂抹

This is a mortar for millet.
这是舂小米用的臼。

To bombard with mortar shells.
用砂浆砌合

He was killed in a mortar attack.
他死于迫击炮炮击。

The farmers pound rice in a mortar.
农民们在臼中舂米。

The enemy was mortarring a hilltop.
敌人正在用迫击炮轰击山头儿。

joint是什么意思：
adj. 联合的
n. 关节，接头
v. 链接，使有接头，焊接

The finger joints are called knuckles.
手指的关节叫做指关节。

It's a really classy joint.
这是一个确实高级的公共场所。

That shop is plain a clip joint
那可是不定一家漫天要价、大敲竹杠的商店啊!

A knobbed bone, as of a knuckle or joint.
指节骨一种圆形突出的骨头，如指关节或关节的

It is a joint venture with private industry.
这是一个与私有企业合资的企业。