磕碰的英文：
1.to knock against; to collide with; to bump against; to hit against

参考例句：

Avoid jogging the camera.
请勿磕碰相机。

The clash of swords was next heard.
接着传来了刀剑磕碰声。

Small children often cry after a minor bump.
小孩子常常是稍微磕碰一下就哭。

The equipment was scratched, dented in places.
这些设备已经有刮痕，有点地方还有磕碰的缺口。

knock是什么意思：
n. 爆震声；敲；敲打
v. 敲；打；击；批评；撞；（心）怦怦跳

Who is knocking the door || Who is knocking || Who is at the door || Who is knocking at the door?
谁在敲门

Who is knocking the door / Who is knocking / Who is at the door / Who is knocking at the door?
谁在敲门

Please knock double knocks at the door before entering.
请先敲两下门再进来。

against是什么意思：
prep. 与...相反；对...不利；倚靠；以防；以...为背景；和...相比

It is against federal law to discriminate against blacks.
歧视黑人是违反联邦法律的。

She was drugged against the pain.
她服麻醉药止痛。

He informed against the drugpusher.
他告发了那个毒品贩。

collide是什么意思：
v. 相撞，碰撞；冲突，不一致

The cars collided at the junction.
汽车在交叉路口相撞。

The interests of the two countries collided.
两国的利益发生冲突。

I collided with a tree.
我撞到了一棵树上。