law
be a law unto yourself behave in a manner that is not conventional or predictable.
the law of diminishing returns: seediminishing.
the law of the jungle: seejungle.
the law of the Medes and Persians: seeMedes.
lay down the law issue instructions to other people in an authoritative or dogmatic way.
the letter of the law: seeletter.
take the law into your own hands punish someone for an offence according to your own ideas of justice, especially in an illegal or violent way.
take someone to law initiate legal proceedings against someone.
there's no law against it used in spoken English to assert that you are doing nothing wrong, especially in response to an actual or implied criticism. informal
someone's word is law: seeword.