at (或in) law

according to or concerned with the laws of a country

依法，与法律有关

an agreement enforceable at law.

可依法实施的协议。

a barrister-at-law.

法律顾问。

be a law unto oneself

behave in a manner that is not conventional or predictable

（行为）反复无常，一意孤行

go to law

resort to legal action in order to settle a matter

诉诸法律

law and order

a situation characterized by respect for and obedience to the rules of a society

治安，法律与秩序

the law of the jungle

lay down the law

issue instructions to other people in an authoritative or dogmatic way

权威性命令，严令

take the law into one's own hands

punish someone for an offence according to one's own ideas of justice, especially in an illegal or violent way

不顾法律擅自处理

take someone to law

initiate legal proceedings against someone

绳之以法

there's no law against it

(informal)used in spoken English to assert that one is doing nothing wrong, especially in response to an actual or implied criticism

(非正式)［口语中表示没有做错，尤用于回应批评］法律又不禁止

I can laugh, can't I? There's no law against it.

我可以笑，不是吗？法律又不禁止。

a law unto (oneself)

A totally independent operator

独断专行：完全独立的经营者

An executive who is a law unto herself.

自行其是的女领导

take the law into (one's) own hands

To mete out justice as one sees fit without due recourse to law enforcement agencies or the courts.

随意处罚：以某人自己觉得适合的方式给予司法处罚，而不通过正当程序诉诸法律执行机关或法庭