Русско-англо-русский юридический словарь

The original concept of a common-law marriage is a marriage that is considered valid by both partners, but has not been formally registered with a state or church registry, or a formal religious service. In effect, the act of the couple representing themselves to others as being married acts as the evidence that they are married. (Wikipedia)

act of terrorism – the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear (vocabulary.com)

Legal system refers to a procedure or process for interpreting and enforcing the law. It elaborates the rights and responsibilities in a variety of ways. Three major legal systems of the world consist of civil law, common law and religious law. (definitions.uslegal.com)

Adultery (anglicised from Latin adulterium) is extramarital sex that is considered objectionable on social, religious, moral or legal grounds. Though what sexual activities constitute adultery varies, as well as the social, religious and legal consequences, the concept exists in many cultures and is similar in Islam, Christianity and Judaism. (Wikipedia)