What term describes a law passed by government that defines legalities in specific situations?

The term that describes a law passed by the government that defines legalities in specific situations is legislation. Legislation refers to the process of making laws and the actual laws that are enacted by a government body, typically a parliament or congress. It sets out the legal frameworks and rules that govern various aspects of society, covering a wide range of issues such as public health, safety, and welfare.

Regulation, while related to legislation, refers to specific rules or directives that are issued by governmental agencies to detail how the laws are to be applied and enforced. Ordinance usually pertains to local laws enacted by municipal authorities, addressing more community-specific issues rather than broader legislative acts. A clause, on the other hand, is a section or provision within a legal document or piece of legislation but does not represent a law in itself. Hence, the most accurate term for a law defined by a government is legislation.